LTE - Random Access Some information concerning PRACH/RACH configuration
1 September 2010 Created by: Peter Stöckl
[email protected] NWS LTE RA E2E SA NE LTE © Nokia Siemens Networks 2010. All rights reserved.
LTE - Random Access Some information concerning PRACH/RACH configuration
LTE - Random Access | 01.09.2010
Table of Contents
1
1 RACH - OVERVIEW ............................................................................................................................ 3 1.1 USED FOR ..................................................................................................................................... 3 1.2 RACH TYPES................................................................................................................................ 3 1.3 PRACH CONFIGURATION .......................................................................................................... 4 2 INVOLVED PARAMETER ..................................................................................................................... 7 2.1 RACH CONFIGURATION ............................................................................................................ 7 2.1.1 PRACH CONFIGURATION INDEX ...................................................................................... 7 2.1.2 PRACH FREQUENCY OFFSET ........................................................................................... 10 2.1.3 PRACH ROOT SEQUENCE ................................................................................................ 16 2.1.4 PRACH CYCLIC SHIFT ...................................................................................................... 18 2.1.5 PRACH HIGH SPEED FLAG .............................................................................................. 21 2.2 RACH TIMING .......................................................................................................................... 21 2.2.1 RANDOM ACCESS RESPONSE WINDOW .......................................................................... 21 2.2.2 MAXIMUM CONTENT RESOLUTION TIMER .................................................................... 22 2.2.3 RANDOM ACCESS BACKOFF .............................................................................................. 22 2.2.4 PREAMBLE TRANSMISSION MAXIMUM ............................................................................ 23 2.2.5 C-RNTI REUSE TIMER ....................................................................................................... 23 2.3 PREAMBLE / PREAMBLE GROUPS ............................................................................................ 24 2.3.1 OVERVIEW .......................................................................................................................... 24 2.3.2 NUMBER OF RA PREAMBLES............................................................................................. 24 2.3.3 RA PREAMBLES GROUP A SIZE......................................................................................... 25 2.3.4 RA MESSAGE POWER OFFSET FOR GROUP B SELECTION ............................................. 25 2.4 MESSAGE SIZE MESSAGE CODING ........................................................................................... 25 2.4.1 LARGE SIZE RA MCS IN UL .............................................................................................. 25 2.4.2 LARGE SIZE RA DATA VOLUME IN UL ............................................................................ 25 2.4.3 SAMLL SIZE RA MCS IN UL .............................................................................................. 26 2.4.4 SMALL SIZE RA DATA VOLUME IN UL ........................................................................... 26 2.4.5 MAX CODERATE FOR RA MSG4 ...................................................................................... 26 2.4.6 MAX CODERATE FOR RA MSG2 (RAR) ........................................................................... 26 2.4.7 MAX NUMBER OF MSG3 HARQ TRANSMISSIONS ......................................................... 27 2.4.8 PDCCH AGGREGATION LEVEL FOR RA MSG4 ............................................................. 27 2.4.9 PDCCH AGGREGATION LEVEL FOR PREAMBLE ASSIGNMENTS ................................... 27 2.4.10 PDCCH AGGREGATION LEVEL FOR RAR..................................................................... 28 2.5 RACH POWER ........................................................................................................................... 28 2.5.1 OVERVIEW POWER RAMPING ........................................................................................... 28 2.5.2 PREAMBLE INITIAL RECEIVED TARGET POWER ............................................................. 28 2.5.3 RA POWER RAMPING SETUP ............................................................................................ 29 2.5.4 POWER RAMPING STEP FOR RA ........................................................................................ 29 2.5.5 TPC COMMAND IN RAR ................................................................................................... 29 3 TYPE OF RACH PROCEDURES ......................................................................................................... 30 3.1 CONTENTION BASED ................................................................................................................ 30
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3.1.1 OVERVIEW .......................................................................................................................... 30 3.1.2 PROCESS WITHOUT PROBLEMS ........................................................................................ 31 3.1.3 PROCESS WITH PROBLEMS PREAMBLE/RAR DETECTION/DECODING.......................... 32 3.1.4 PROCESS WITH PROBLEMS MSG3 PROBLEMS ................................................................. 33 3.2 CONTENTION FREE ................................................................................................................... 34 3.2.1 OVERVIEW .......................................................................................................................... 34 3.2.2 PROCESS .............................................................................................................................. 35 4 RACH/PRACH PLANNING/DIMENSIONING .................................................................................. 36 4.1 RECOMMENDATION .................................................................................................................. 36 4.2 PREAMBLE SELECTION ............................................................................................................. 36 4.2.1 NORMAL CELL.................................................................................................................... 36 4.2.2 HIGH SPEED CELL ............................................................................................................. 38 5 PM-COUNTER ................................................................................................................................... 42 5.1 NUMBER OF AVAILABLE RACH CHANNELS............................................................................ 42 5.2 RACH SETUP ATTEMPTS .......................................................................................................... 42 5.3 RACH SETUP COMPLETIONS ................................................................................................... 43 5.4 UL PRB UTILIZATION PER PRACH, PUCCH, PUSCH ........................................................ 43 6 REFERENCES ...................................................................................................................................... 45
2
1 RACH - Overview 1.1 Used for Relevant scenarios for RACH usage: •
UE in RRC connected state / not uplink-synchronized need to send new UL data or control information
•
UE in RRC connected state / not uplink-synchronized need to receive new DL data and therefore had to transmit ACK/NACK in UL
•
UE in RRC connected state / handing over from current serving cell to a target cell
•
Transition from RRC_IDLE to RRC Connected state (e.g. initial access or tracking area update)
•
Recovering from radio link failure
•
Exceptional an uplink-synchronized UE is allowed to send a SR if it has no other UL resource to send the SR.
1.2 RACH types Contention-based: (implying an inherent risk of collision) Contention based Radom Access Procedure
UE
eNB Random Access Preamble ( on PRACH)
( with embedded1- bit indication for L 2/L 3 message size)
1
Random Access Response ( on PDCCH+ PDSCH) ( Timing Adjustment,C- RNTI, UL grant for L2/ 3 message..)
LTE - Random Access | 01.09.2010
2
3
L2/L 3 message (
PUSCH transmission including contentin resolution identity)
3
Contention resolution Message 4 Peter Stöckl Network Engineering March 2010
Contention-free Contention Free Random Access Procedure
UE
eNB
Random Access Preamble Assignment 0 Random Access Preamble ( on PRACH)
1
Random Access Respoonse ( on PDCCH+ PDSCH)
2
For new downlink data or HO eNB has the option of allocating a dedicated signature to a UE => contention free access is possible => faster than contention based and therefore better for time-critical procedures like HO Peter Stöckl Network Engineering March 2010
1.3 PRACH Configuration
•
PRACH not in PUCCH area
•
Time-frequency resource semi-statically allocated within PUSCH
•
Periodicity: Once in 20ms up to every sub-frame / max one RACH resource per subframe
•
Bandwidth: 6 PRBs (1.08MHz) / (for 1.4 MHz system whole bandwidth) (Sub-carrier spacing 1.5kHz for Preamble Format 0-3 and 7.5kHz for Preamble Format 4)
LTE - Random Access | 01.09.2010
Multiplexing of PRACH with PUSCH & PUCCH:
4
~ 1 data subcarrier guard band
• • •
864 subcarriers
ΔfRA = 1.25kHz
Δf = 15kHz
72 subcarriers (6 RBs)
~ 1 data subcarrier guard band
839 subcarrieres (sc)
12.5 sc
PRACH
12.5 sc
PUSCH
FDD – the start of the RACH burst shall be aligned with UL sub-frame assuming timing advance of zero TDD - for preamble formats 0-3 – the start of the RACH burst shall be aligned with the UL sub-frame assuming timing advance of zero TDD – for preamble format 4 – the start of the RACH burst shall be 4832 * Ts (Ts = 1 / 30.72 MHz ) before the end of the UpPTS at the UE, where the UpPTS is referenced to the UE’s uplink frame timing assuming timing advance of zero.
LTE - Random Access | 01.09.2010
Formats:
5
•
Length typically one sub-frame (0.1ms CP + 0.8ms Preamble sequence + 0.1ms guard period)
•
Four different formats available for different environments (e.g. large cells..) (5 formats for TDD)
903µs 800µs
Format 0
CP
Preamble Sequence
1.08MHz (6 PRBs)
103µs 1484µs
CP
Format 1
Preamble Sequence 800µs
684µs 1803µs
Format 2
CP
Preamble Sequence
203µs
800µs
Preamble Sequence 800µs
CP
Preamble Sequence
Preamble Sequence
684µs
800µs
800µs
Format 3
Preamble Format
TCP [µs]
TSEQ [µs]
Typical usage
0
103.13
800
Normal 1 ms RA burst with 800 µs preamble sequence, for small-medium cells (up to ~14 km)
1
684.38
800
2 ms RA burst with 800 µs preamble sequence, for large cells (up to ~77 km) without a link budget problem
2
203.13
1600
2 ms RA burst with 1600 µs preamble sequence, for medium cell (up to ~29 km) and increased path loss
3
684.38
1600
3 ms RA burst with 1600 µs preamble sequence, for very large cells (up to ~100 km) and increased path loss
4
14.58
133.33
Frame structure type 2 and special subframe configurations with UpPTS lengths 4384 Ts and 5120 Ts only. [Ts = 1 / 30.72MHz] (up to 1.4 km cell range)
Zadoff-Chu sequences with length 839 (prime number) for Preamble Format 0-3 and 139 for Preamble Format 4 are used •
•
Available Sequences. o
838 for Preamble Format 0-3
o
138 for Preamble Format 4
Cyclic shifts: o
16 for Preamble Format 0-3
o
6 for Preamble Format 4
LTE - Random Access | 01.09.2010
2284µs
6
•
Detection is sensitive to considerable Doppler shifts => special rules for high speed cells
•
UE selects preamble from 64 different sequences configured for each cell
RACH Procedure Overview •
UE selects randomly a preamble from the list of preambles broadcasted in the BCCH
•
UE calculates OLPC (open loop power control) parameters (Initial Tx Power)
•
UE checks contention parameters (i.e. max number of retries)
•
UE transmits initial RACH and waits for a response before retry. Open loop PC ensures that each retry will be at a higher level.
•
Upon receipt of successful UL RACH preamble eNB calculates power adjustment and timing advance parameters together with an UL capacity grant.
2 Involved Parameter (Remark: Based on RL10 for FDD and RL15TD for TDD)
2.1 RACH Configuration 2.1.1 PRACH Configuration Index
LTE - Random Access | 01.09.2010
FDD
7
Name:
prachConfIndex:
Description:
PRACH Configuration Index: Defines allowed System frame and sub-frame numbers for random access attempts, and the preamble format
Range/Step:
3...24, step 1
Default:
3
Remark:
For more information see table below. The highlighted configurations are supported by RL10
PRACH Configuration Index
Subframe #
PRACH Configuration Index
Preamble Format
System frame #
Subframe #
Even
1
32
2
Even
1
0
Even
4
33
2
Even
4
0
Even
7
34
2
Even
7
Preamble Format
System frame #
0
0
1 2
Subframe #
PRACH Configuration Index
Any
1
0
Any
5
0
6
Preamble Format
System frame #
Preamble Format
System frame #
Subframe #
3
0
35
2
Any
1
4
4
36
2
Any
4
Any
7
37
2
Any
7
0
Any
1, 6
38
2
Any
1, 6
7
0
Any
2 ,7
39
2
Any
2 ,7
8
0
Any
3, 8
40
2
Any
3, 8
9
0
Any
1, 4, 7
41
2
Any
1, 4, 7
10
0
Any
2, 5, 8
42
2
Any
2, 5, 8
11
0
Any
3, 6, 9
43
2
Any
3, 6, 9
12
0
Any
0, 2, 4, 6, 8
44
2
Any
0, 2, 4, 6, 8
13
0
Any
1, 3, 5, 7, 9
45
2
Any
1, 3, 5, 7, 9
14
0
Any
0, 1, 2, 3, 4, 5, 6, 7, 8, 9
46
N/A
N/A
N/A
15
0
Even
9
47
2
Even
9
16
1
Even
1
48
3
Even
1
17
1
Even
4
49
3
Even
4
18
1
Even
7
50
3
Even
7
19
1
Any
1
51
3
Any
1
20
1
Any
4
52
3
Any
4
21
1
Any
7
53
3
Any
7
22
1
Any
1, 6
54
3
Any
1, 6
23
1
Any
2 ,7
55
3
Any
2 ,7
24
1
Any
3, 8
56
3
Any
3, 8
25
1
Any
1, 4, 7
57
3
Any
1, 4, 7
26
1
Any
2, 5, 8
58
3
Any
2, 5, 8
27
1
Any
3, 6, 9
59
3
Any
3, 6, 9
28
1
Any
0, 2, 4, 6, 8
60
N/A
N/A
N/A
29
1
Any
1, 3, 5, 7, 9
61
N/A
N/A
N/A
LTE - Random Access | 01.09.2010
PRACH Configuration Index
8
PRACH Configuration Index
Subframe #
PRACH Configuration Index
N/A
N/A
Even
9
Preamble Format
System frame #
30
N/A
31
1
Preamble Format
System frame #
Subframe #
62
N/A
N/A
N/A
63
3
Even
9
LTE - Random Access | 01.09.2010
TDD
9
Name:
prachConfIndex:
Description:
PRACH Configuration Index: Defines allowed System frame and sub-frame numbers for random access attempts, and the preamble format
Range/Step:
3...53, step 1
Default:
3
Remark:
For more information see table below. The highlighted configurations are supported by RL15TD. PRACH Configuration Index within range 23…25 and 33…35 can be used only when tddUplinkDownlinkConf [ulDlConfTD] is set to ‘sa1’ and tddSpecialSubframeConf [spcSubConfTD] is set to ‘ssp5’. See next table for PRACH Configuration Index, Preamble Format and RACH Density.
Preamble Format
Density per 10ms (DRA)
Preamble Format
Density per 10ms (DRA)
Version (rRA)
0
0
32
2
0.5
2
1
1
33
2
1
0
0.5
2
34
2
1
1
0
1
0
35
2
2
0
4
0
1
1
36
2
3
0
5
0
1
2
37
2
4
0
6
0
2
0
38
2
5
0
7
0
2
1
39
2
6
0
8
0
2
2
40
3
0.5
0
9
0
3
0
41
3
0.5
1
10
0
3
1
42
3
0.5
2
11
0
3
2
43
3
1
0
12
0
4
0
44
3
1
1
13
0
4
1
45
3
2
0
PRACH Configuration Index
Version (rRA)
PRACH Configuration Index
0.5
0
0
0.5
2
0
3
Preamble Format
Density per 10ms (DRA)
Preamble Format
Density per 10ms (DRA)
Version (rRA)
14
0
46
3
3
0
15
0
47
3
4
0
5
1
48
4
0.5
0
0
5
2
49
4
0.5
1
18
0
6
0
50
4
0.5
2
19
0
6
1
51
4
1
0
20
1
0.5
0
52
4
1
1
21
1
0.5
1
53
4
2
0
22
1
0.5
2
54
4
3
0
23
1
1
0
55
4
4
0
24
1
1
0
56
4
5
0
25
1
2
0
57
4
6
0
26
1
3
0
58
N/A
N/A
N/A
27
1
4
0
59
N/A
N/A
N/A
28
1
5
0
60
N/A
N/A
N/A
29
1
6
0
61
N/A
N/A
N/A
30
2
0.5
0
62
N/A
N/A
N/A
31
2
0.5
1
63
N/A
N/A
N/A
PRACH Configuration Index
Version (rRA)
PRACH Configuration Index
4
2
0
5
16
0
17
2.1.2 PRACH Frequency Offset
Name:
prachFreqOff
Description:
PRACH Frequency Offset: First physical resource block available for PRACH in the UL system frequency band.
Range/Step:
0...94, step 1
Default:
1
Remark:
The values for the parameter PRACH FrequencyOffset should be set in such a way that overlapping of PRACH with PUCCH is avoided, however positioning the PRACH nearby one of the two side of the BW in order to maximize the PUSCH area manageable by the scheduler. If X is the total number of PUCCH
LTE - Random Access | 01.09.2010
FDD
10
resources the PRACH FrequencyOffset shall be calculated as given below: 1.
when PRACH is near to the right side of the BW:
prach-FrequencyOffset = 2.
UL N RB − 6 − X 2
when PRACH is near to the left side of the BW: X
prach-FrequencyOffset = 2 , where is floor operation to round the elements of to the nearest integers towards plus infinity. For example in the case of BW 20MHz, the number of PRB is 100 and MaxNbrOfOFDMSymsForPDCCH =3 the total PUCCH resource are 9 and therefore: prach-FrequencyOffset = 100 - 6 - 5 = 94 - 5 = 89 (if PRACH shall be placed on the right side) or prach-FrequencyOffset = 5 (if PRACH shall be placed on the left side) As said above the configuration of PRACH Offset according to tone of the above formulas is not mandatory but guarantees the non overlapping of PUCCH signaling with PRACH and at the same time maximize the UL scheduler performance providing the largest possible area available for scheduling to PUSCH. In RL09 the scheduler can handle only one PUSCH area.
LTE - Random Access | 01.09.2010
TDD
11
Name:
prachFreqOff
Description:
PRACH Frequency Offset: First physical resource block available for PRACH in the UL system frequency band.
Range/Step:
0...94, step 1
Default:
1
Remark:
In case preamble format 4 is selected prachFreqOff must be set to 0. For preamble format 0-3, the values for the parameter PRACH FrequencyOffset should be set in such a way that overlapping of PRACH with PUCCH is avoided, however positioning the PRACH nearby the border of the BW in order to maximize the PUSCH area manageable by the scheduler. The mapping of the random access preamble in time and frequency can be
taken out of the following table. The quadruples (fRA, t0RA, t1RA, t2RA) in this table indicate the location of a specific random access resource where indicates a frequency resource within the considered time instance
fRA
t0RA =0,1;2 indicates whether the random access resource is reoccurring in all radio frames, in even radio frames, or in odd radio frames t1RA =0,1
indicates whether the random access resource is located in first half frame or in second half frame
t2RA
indicates the uplink sub-frame number where the preamble starts, counting from 0 at the first uplink sub-frame between 2 consecutive downlink-to-uplink switch points, with the exception of preamble format 4 where it is denoted as (*)
Frequency multiplexing for preamble format 0-3 shall be done according to:
𝑅𝐴 𝑛𝑃𝑅𝐵
𝑓𝑅𝐴 𝑝𝑟𝑎𝑐ℎ𝐹𝑟𝑒𝑞𝑂𝑓𝑓 + 6 � � 2 = � 𝑓𝑅𝐴 𝑈𝐿 𝑁𝑅𝐵 − 6 − 𝑝𝑟𝑎𝑐ℎ𝐹𝑟𝑒𝑞𝑂𝑓𝑓 − 6 � � 2
where 𝑈𝐿 𝑁𝑅𝐵
𝑅𝐴 𝑛𝑃𝑅𝐵
𝑖𝑓 𝑓𝑅𝐴 𝑚𝑜𝑑2 = 0 𝑜𝑡ℎ𝑒𝑟𝑤𝑖𝑠𝑒
is the number of uplink resource blocks is the first physical resource block allocated to the PRACH opportunity
and 𝑈𝐿 −6 0 ≤ 𝑝𝑟𝑎𝑐ℎ𝐹𝑟𝑒𝑞𝑂𝑓𝑓 ≤ 𝑁𝑅𝐵
6 𝑓𝑅𝐴 𝑅𝐴 = � 𝑈𝐿 𝑛𝑃𝑅𝐵 𝑁𝑅𝐵 − 6 (𝑓𝑅𝐴 + 1)
1 𝑖𝑓 ��𝑛𝑓 𝑚𝑜𝑑2� ∗ (2 − 𝑁𝑆𝑃 ) + 𝑡𝑅𝐴 � 𝑚𝑜𝑑2 = 0
where 𝑛𝑓
𝑁𝑆𝑃
𝑜𝑡ℎ𝑒𝑟𝑤𝑖𝑠𝑒
is the system frame number is the number of DL to UL switch points within the radio frame
LTE - Random Access | 01.09.2010
and for preamble format 4 according to :
12
PRACH Configuration Index
(0,1,0,2) (0,1,0,1) (0,1,0,0) (0,1,0,2) (0,1,0,1) (0,1,0,0) (0,1,0,2)
1 2 3 4
(0,2,0,2) (0,1,1,2) (0,0,0,2) (0,0,1,2)
(0,2,0,1) (0,1,1,1) (0,0,0,1) (0,0,1,1)
5 6
(0,0,0,1) (0,0,0,2) (0,0,1,2) (0,0,0,1) (0,0,1,1) (0,0,0,0) (0,0,1,0)
(0,0,0,0) N/A (0,0,0,0) N/A N/A (0,0,0,1) (0,0,0,1) (0,0,0,0) (0,0,0,1) (0,0,0,0) (0,0,0,0) (0,0,0,2) (0,0,1,1) (0,0,1,0) (0,0,0,2) (0,0,0,1) (1,0,0,0) (0,0,1,1) (0,0,0,0) N/A (0,0,0,0) N/A N/A (0,0,0,1) (0,0,1,0) (0,0,0,2) (0,0,1,0) N/A N/A (0,0,0,0) N/A N/A (0,0,0,0) (0,0,0,1) (0,0,1,1)
(0,0,0,1) (0,0,0,2) (0,0,1,2) (0,0,0,0) (0,0,1,0) (0,0,1,1) N/A
(0,0,0,0) (0,0,0,1) (0,0,1,1) (0,0,0,1) (0,0,1,0) (0,0,1,1) (0,0,0,0) (0,0,0,1) (0,0,1,0)
(0,0,0,1) (0,0,0,2) (0,0,1,1) (0,0,1,2) (0,0,0,0) (0,0,0,2) (0,0,1,0) (0,0,1,2) (0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,1) (0,0,1,2) (0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,1) (0,0,1,2)
(0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) N/A
8 9
10
11
12
13
14
LTE - Random Access | 01.09.2010
sa6
0
7
13
sa0
tddUplinkDownlinkConf [ulDlConfTD] sa1 sa2 sa3 sa4 sa5
15
16
N/A
(0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (1,0,0,1) (0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (1,0,1,1)
(0,2,0,0) (0,1,1,0) (0,0,0,0) (0,0,1,0)
(0,2,0,2) (0,1,0,1) (0,0,0,2) (0,0,0,1)
(0,2,0,1) (0,2,0,0) (0,2,0,2) (0,1,0,0) N/A (0,1,1,1) (0,0,0,1) (0,0,0,0) (0,0,0,2) (0,0,0,0) N/A (0,0,1,1)
(0,0,0,0) (0,0,0,0) (0,0,0,0) (0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,0,1) (0,0,0,1) (1,0,0,0) (0,0,0,2) (1,0,0,0) (0,0,0,2) (1,0,0,1) (2,0,0,0) (0,0,1,1) (0,0,0,0) N/A (0,0,0,0) N/A 0,0,0,0) (0,0,1,0) (0,0,0,1) (0,0,0,2) (1,0,1,0) (1,0,0,0) (0,0,1,0) N/A N/A N/A N/A (0,0,0,1) (0,0,1,0) (0,0,1,1) (0,0,0,0) (0,0,0,0) (0,0,0,0) (0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,0,1) (0,0,0,1) (1,0,0,0) (0,0,0,2) (1,0,0,0) (0,0,0,2) (1,0,0,0) (2,0,0,0) (0,0,1,0) (1,0,1,0) (1,0,0,2) (1,0,0,1) (3,0,0,0) (0,0,1,1) N/A (0,0,0,0) N/A N/A (0,0,0,0) (0,0,0,1) (0,0,0,1) (0,0,0,2) (0,0,0,2) (1,0,0,1) (0,0,1,1) N/A (0,0,0,0) N/A N/A (0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,0,2) (0,0,1,0) (1,0,0,0) (0,0,1,1) (0,0,0,0) (0,0,0,0) (0,0,0,0) (0,0,0,0) (0,0,0,0) (0,0,1,0) (0,0,0,1) (0,0,0,1) (1,0,0,0) (0,0,0,1) (1,0,0,0) (0,0,0,2) (1,0,0,0) (2,0,0,0) (0,0,0,2) (1,0,1,0) (1,0,0,1) (1,0,0,1) (3,0,0,0) (0,0,1,0) (2,0,0,0) (1,0,0,2) (2,0,0,1) (4,0,0,0) (0,0,1,1) (0,0,0,0) (0,0,0,0) (0,0,0,0) N/A N/A (0,0,1,0) (0,0,0,1) (0,0,0,1) (1,0,0,0) (0,0,0,2) (1,0,0,0) (1,0,1,0) (1,0,0,0) (1,0,0,1) (2,0,1,0) (1,0,0,2) (2,0,0,0)
17
sa0
tddUplinkDownlinkConf [ulDlConfTD] sa1 sa2 sa3 sa4 sa5
19
(0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,2) (0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,1) (0,0,1,2) N/A
20 / 30 21 / 31 22 / 32 23 / 33
(0,1,0,1) (0,2,0,1) (0,1,1,1) (0,0,0,1)
(0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (1,0,0,0) (0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (1,0,0,1) (1,0,1,1) (0,0,0,0) (0,0,0,1) (0,0,1,0) (0,0,1,1) (1,0,0,0) (1,0,1,0) (0,1,0,0) (0,2,0,0) (0,1,1,0) (0,0,0,0)
24 / 34 25 / 35
(0,0,1,1) (0,0,0,1) (0,0,1,1) (0,0,0,1) (0,0,1,1) (1,0,0,1) (0,0,0,1) (0,0,1,1) (1,0,0,1) (1,0,1,1) (0,0,0,1) (0,0,1,1) (1,0,0,1) (1,0,1,1) (2,0,0,1)
(0,0,1,0) (0,0,0,0) (0,0,1,0) (0,0,0,0) (0,0,1,0) (1,0,0,0) (0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) (0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) (2,0,0,0)
(0,0,0,1) (0,0,1,1) (1,0,0,1) (1,0,1,1) (2,0,0,1) (2,0,1,1) (0,1,0,0)
(0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) (2,0,0,0) (2,0,1,0) N/A
18
26 / 36
27 / 37
28 / 38
29 /39
40
N/A
(0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) (2,0,0,0) (2,0,1,0) N/A
(0,0,0,0) (0,0,0,1) (0,0,0,2) (1,0,0,0) (1,0,0,1) (0,0,0,0) (0,0,0,1) (0,0,0,2) (1,0,0,0) (1,0,0,1) (1,0,0,2) N/A
N/A
N/A
N/A
(0,0,0,0) (0,0,0,1) (1,0,0,0) (1,0,0,1) (2,0,0,0) (2,0,0,1) N/A
(0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) (4,0,0,0) (5,0,0,0) N/A
(0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,1) (1,0,0,2) (0,0,0,0) (0,0,0,1) (0,0,0,2) (0,0,1,0) (0,0,1,1) (1,0,1,1) (0,1,0,1) (0,2,0,1) (0,1,1,0) (0,0,0,1)
N/A N/A N/A N/A
(0,1,0,1) (0,1,0,0) (0,2,0,1) (0,2,0,0) N/A N/A (0,0,0,1) (0,0,0,0)
N/A N/A N/A N/A
N/A N/A
N/A (0,0,0,1) (1,0,0,1) (0,0,0,1) (1,0,0,1) (2,0,0,1) (0,0,0,1) (1,0,0,1) (2,0,0,1) (3,0,0,1) (0,0,0,1) (1,0,0,1) (2,0,0,1) (3,0,0,1) (4,0,0,1)
N/A (0,0,0,0) (1,0,0,0) (0,0,0,0) (1,0,0,0) (2,0,0,0) (0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) (0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) (4,0,0,0)
N/A N/A
(0,0,0,1) (1,0,0,1) (2,0,0,1) (3,0,0,1) (4,0,0,1) (5,0,0,1) (0,1,0,0)
(0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) (4,0,0,0) (5,0,0,0) N/A
N/A
N/A
N/A
N/A
N/A
sa6
N/A
N/A
N/A
N/A
N/A
(0,0,1,0) (0,0,0,1) (0,0,1,0) (0,0,0,1) (0,0,1,0) (1,0,0,1) (0,0,0,1) (0,0,1,0) (1,0,0,1) (1,0,1,0) (0,0,0,1) (0,0,1,0) (1,0,0,1) (1,0,1,0) (2,0,0,1) (0,0,0,1) (0,0,1,0) (1,0,0,1) (1,0,1,0) (2,0,0,1) (2,0,1,0) (0,1,0,0)
LTE - Random Access | 01.09.2010
PRACH Configuration Index
14
PRACH Configuration Index
sa0
41
(0,2,0,0)
N/A
N/A
(0,2,0,0)
N/A
N/A
(0,2,0,0)
42 43 44 45
(0,1,1,0) (0,0,0,0) (0,0,1,0) (0,0,0,0) (0,0,1,0) (0,0,0,0) (0,0,1,0) (1,0,0,0) (0,0,0,0) (0,0,1,0) (1,0,0,0) (1,0,1,0) (0,1,0,*) (0,2,0,*) (0,1,1,*) (0,0,0,*) (0,0,1,*) (0,0,0,*) (0,0,1,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (2,0,1,*) N/A N/A N/A N/A
N/A N/A N/A N/A
N/A N/A N/A N/A
N/A N/A N/A N/A
N/A N/A N/A N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
(0,1,0,*) (0,2,0,*) (0,1,1,*) (0,0,0,*) (0,0,1,*) (0,0,0,*) (0,0,1,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (2,0,1,*) N/A N/A N/A N/A
(0,1,0,*) (0,2,0,*) (0,1,1,*) (0,0,0,*) (0,0,1,*) (0,0,0,*) (0,0,1,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (2,0,1,*) N/A N/A N/A N/A
N/A (0,0,0,0) N/A (0,0,0,0) (1,0,0,0) (0,0,0,0) (1,0,0,0) (2,0,0,0) (0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) (0,1,0,*) (0,2,0,*) N/A (0,0,0,*) N/A (0,0,0,*) (1,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) (5,0,0,*) N/A N/A N/A N/A
(0,1,0,*) (0,2,0,*) N/A (0,0,0,*) N/A (0,0,0,*) (1,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) (5,0,0,*) N/A N/A N/A N/A
(0,1,0,*) (0,2,0,*) N/A (0,0,0,*) N/A (0,0,0,*) (1,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) (0,0,0,*) (1,0,0,*) (2,0,0,*) (3,0,0,*) (4,0,0,*) (5,0,0,*) N/A N/A N/A N/A
N/A (0,0,0,0) N/A (0,0,0,0) (1,0,0,0) (0,0,0,0) (1,0,0,0) (2,0,0,0) (0,0,0,0) (1,0,0,0) (2,0,0,0) (3,0,0,0) (0,1,0,*) (0,2,0,*) (0,1,1,*) (0,0,0,*) (0,0,1,*) (0,0,0,*) (0,0,1,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (0,0,0,*) (0,0,1,*) (1,0,0,*) (1,0,1,*) (2,0,0,*) (2,0,1,*) N/A N/A N/A N/A
46
47
48 49 50 51 52 53 54
55
LTE - Random Access | 01.09.2010
56
15
57
58 59 60 61
tddUplinkDownlinkConf [ulDlConfTD] sa1 sa2 sa3 sa4 sa5
sa6
PRACH Configuration Index
sa0
tddUplinkDownlinkConf [ulDlConfTD] sa1 sa2 sa3 sa4 sa5
sa6
62
N/A
N/A
N/A
N/A
N/A
N/A
N/A
63
N/A
N/A
N/A
N/A
N/A
N/A
N/A
2.1.3 PRACH Root sequence Name:
rootSeqIndex:
Description:
RACH Root Sequence: The preamble generation is started from the Root Sequence which is pointed by the logical root sequence number. 64 preambles can be transmitted in the PRACH frame. If one root is not enough to generate all the 64 preambles, then the consecutive number is selected until the full set is generated. RACH root sequence is cell specific information and neighboring cells should have a different value. RACH root sequence is transmitted in system information.
Range/Step:
0...837, step 1 / for preamble format 0-3 0…137, step 1 / for preamble format 4
Default:
-
Remark:
see tables below (Source: 3GPP 36.211 Table 5.7.2-4 / and Table 5.7.2-5)
Physical root sequence index u (in increasing order of the corresponding logical sequence number) Preamble formats 0-3
0–23
129, 710, 140, 699, 120, 719, 210, 629, 168, 671, 84, 755, 105, 734, 93, 746, 70, 769, 60, 779, 2, 837, 1, 838
24–29
56, 783, 112, 727, 148, 691
30–35
80, 759, 42, 797, 40, 799
36–41
35, 804, 73, 766, 146, 693
42–51
31, 808, 28, 811, 30, 809, 27, 812, 29, 810
52–63
24, 815, 48, 791, 68, 771, 74, 765, 178, 661, 136, 703
64–75
86, 753, 78, 761, 43, 796, 39, 800, 20, 819, 21, 818
76–89
95, 744, 202, 637, 190, 649, 181, 658, 137, 702, 125, 714, 151, 688
90–115
217, 622, 128, 711, 142, 697, 122, 717, 203, 636, 118, 721, 110, 729, 89, 750, 103, 736, 61, 778, 55, 784, 15, 824, 14, 825
116–135
12, 827, 23, 816, 34, 805, 37, 802, 46, 793, 207, 632, 179, 660, 145, 694, 130, 709, 223, 616
136–167
228, 611, 227, 612, 132, 707, 133, 706, 143, 696, 135, 704, 161, 678, 201, 638, 173, 666, 106, 733, 83, 756, 91, 748, 66, 773, 53, 786, 10, 829,
LTE - Random Access | 01.09.2010
Logical root sequence number
16
Logical root sequence number
Physical root sequence index u (in increasing order of the corresponding logical sequence number) Preamble formats 0-3
LTE - Random Access | 01.09.2010
9, 830
17
168–203
7, 832, 8, 831, 16, 823, 47, 792, 64, 775, 57, 782, 104, 735, 101, 738, 108, 731, 208, 631, 184, 655, 197, 642, 191, 648, 121, 718, 141, 698, 149, 690, 216, 623, 218, 621
204–263
152, 687, 144, 695, 134, 705, 138, 701, 199, 640, 162, 677, 176, 663, 119, 720, 158, 681, 164, 675, 174, 665, 171, 668, 170, 669, 87, 752, 169, 670, 88, 751, 107, 732, 81, 758, 82, 757, 100, 739, 98, 741, 71, 768, 59, 780, 65, 774, 50, 789, 49, 790, 26, 813, 17, 822, 13, 826, 6, 833
264–327
5, 834, 33, 806, 51, 788, 75, 764, 99, 740, 96, 743, 97, 742, 166, 673, 172, 667, 175, 664, 187, 652, 163, 676, 185, 654, 200, 639, 114, 725, 189, 650, 115, 724, 194, 645, 195, 644, 192, 647, 182, 657, 157, 682, 156, 683, 211, 628, 154, 685, 123, 716, 139, 700, 212, 627, 153, 686, 213, 626, 215, 624, 150, 689
328–383
225, 614, 224, 615, 221, 618, 220, 619, 127, 712, 147, 692, 124, 715, 193, 646, 205, 634, 206, 633, 116, 723, 160, 679, 186, 653, 167, 672, 79, 760, 85, 754, 77, 762, 92, 747, 58, 781, 62, 777, 69, 770, 54, 785, 36, 803, 32, 807, 25, 814, 18, 821, 11, 828, 4, 835
384–455
3, 836, 19, 820, 22, 817, 41, 798, 38, 801, 44, 795, 52, 787, 45, 794, 63, 776, 67, 772, 72, 767, 76, 763, 94, 745, 102, 737, 90, 749, 109, 730, 165, 674, 111, 728, 209, 630, 204, 635, 117, 722, 188, 651, 159, 680, 198, 641, 113, 726, 183, 656, 180, 659, 177, 662, 196, 643, 155, 684, 214, 625, 126, 713, 131, 708, 219, 620, 222, 617, 226, 613
456–513
230, 609, 232, 607, 262, 577, 252, 587, 418, 421, 416, 423, 413, 426, 411, 428, 376, 463, 395, 444, 283, 556, 285, 554, 379, 460, 390, 449, 363, 476, 384, 455, 388, 451, 386, 453, 361, 478, 387, 452, 360, 479, 310, 529, 354, 485, 328, 511, 315, 524, 337, 502, 349, 490, 335, 504, 324, 515
514–561
323, 516, 320, 519, 334, 505, 359, 480, 295, 544, 385, 454, 292, 547, 291, 548, 381, 458, 399, 440, 380, 459, 397, 442, 369, 470, 377, 462, 410, 429, 407, 432, 281, 558, 414, 425, 247, 592, 277, 562, 271, 568, 272, 567, 264, 575, 259, 580
562–629
237, 602, 239, 600, 244, 595, 243, 596, 275, 564, 278, 561, 250, 589, 246, 593, 417, 422, 248, 591, 394, 445, 393, 446, 370, 469, 365, 474, 300, 539, 299, 540, 364, 475, 362, 477, 298, 541, 312, 527, 313, 526, 314, 525, 353, 486, 352, 487, 343, 496, 327, 512, 350, 489, 326, 513, 319, 520, 332, 507, 333, 506, 348, 491, 347, 492, 322, 517
630–659
330, 509, 338, 501, 341, 498, 340, 499, 342, 497, 301, 538, 366, 473, 401, 438, 371, 468, 408, 431, 375, 464, 249, 590, 269, 570, 238, 601, 234, 605
660–707
257, 582, 273, 566, 255, 584, 254, 585, 245, 594, 251, 588, 412, 427, 372, 467, 282, 557, 403, 436, 396, 443, 392, 447, 391, 448, 382, 457, 389, 450, 294, 545, 297, 542, 311, 528, 344, 495, 345, 494, 318, 521, 331, 508, 325, 514, 321, 518
708–729
346, 493, 339, 500, 351, 488, 306, 533, 289, 550, 400, 439, 378, 461,
Physical root sequence index u (in increasing order of the corresponding logical sequence number) Preamble formats 0-3
Logical root sequence number
374, 465, 415, 424, 270, 569, 241, 598 730–751
231, 608, 260, 579, 268, 571, 276, 563, 409, 430, 398, 441, 290, 549, 304, 535, 308, 531, 358, 481, 316, 523
752–765
293, 546, 288, 551, 284, 555, 368, 471, 253, 586, 256, 583, 263, 576
766–777
242, 597, 274, 565, 402, 437, 383, 456, 357, 482, 329, 510
778–789
317, 522, 307, 532, 286, 553, 287, 552, 266, 573, 261, 578
790–795
236, 603, 303, 536, 356, 483
796–803
355, 484, 405, 434, 404, 435, 406, 433
804–809
235, 604, 267, 572, 302, 537
810–815
309, 530, 265, 574, 233, 606
816–819
367, 472, 296, 543
820–837
336, 503, 305, 534, 373, 466, 280, 559, 279, 560, 419, 420, 240, 599, 258, 581, 229, 610
Logical root sequence number 0–19
1
138
2
137
3
136
4
135
5
134
6
133
7
132
8
131
9
130
10
129
20–39
11
128
12
127
13
126
14
125
15
124
16
123
17
122
18
121
19
120
20
119
40–59
21
118
22
117
23
116
24
115
25
114
26
113
27
112
28
111
29
110
30
109
60–79
31
108
32
107
33
106
34
105
35
104
36
103
37
102
38
101
39
100
40
99
80–99
41
98
42
97
43
96
44
95
45
94
46
93
47
92
48
91
49
90
50
89
100–119
51
88
52
87
53
86
54
85
55
84
56
83
57
82
58
81
59
80
60
79
120–137
61
78
62
77
63
76
64
75
65
74
66
73
67
72
68
71
69
70
-
-
138–837
N/A
2.1.4 PRACH Cyclic Shift Name:
prachCS
LTE - Random Access | 01.09.2010
Physical root sequence index u (in increasing order of the corresponding logical sequence number) Preamble format 4
18
LTE - Random Access | 01.09.2010
19
Description:
PRACH Cyclic Shift: Preamble cyclic shift defines the configuration which is used for preamble generation. The configuration determines how many cyclic shifts are needed to generate preamble. Unrestricted set is supported. Configuration also defines the zero correlation zone and respective maximum cell range.
Range/Step:
0...15, step 1
Default:
-
Remark:
For more information please see tables below: NCS for preamble generation (preamble formats 0-3) NCS value
NCS configuration
Unrestricted set
Restricted set
0
0
15
1
13
18
2
15
22
3
18
26
4
22
32
5
26
38
6
32
46
7
38
55
8
46
68
9
59
82
10
76
100
11
93
128
12
119
158
13
167
202
14
279
237
15
419
-
NCS configuration
NCS value
0
2
1
4
2
6
3
8
4
10
5
12
6
15
7
N/A
8
N/A
9
N/A
10
N/A
11
N/A
12
N/A
13
N/A
14
N/A
15
N/A
LTE - Random Access | 01.09.2010
NCS for preamble generation (preamble format 4) Remark: RL15TD supports NCS configuration 4,5 and 6
20
NCS values in relation to Preamble Format and Cell Range 14.53 km
29.53 km
Format 1 Format 1 & 3 Format 0 13 – 0.79 km 18 – 1.51 km 26 – 2.65 km 38 – 4.37 km 59 – 7.37 km 93 – 12.23 km
167 – 22.82 km
119 – 15.95 km
419 – 58.86 km
279 – 38.84 km
839 (=0) – 118.93 km
76 – 9.80 km 46 – 5.51 km 32 – 3.51 km 22 – 2.08 km 15 – 1.08 km
2.1.5 PRACH High Speed Flag Name:
prachHsFlag
Description:
PRACH High Speed Flag: High speed flag for PRACH preamble generation determines whether an unrestricted or a restricted set has to be used by UE. The unrestricted set, and thus the parameter value 'false', is supported.
Range/Step:
false
Default:
false
2.2 RACH Timing
LTE - Random Access | 01.09.2010
2.2.1 Random Access Response Window
21
Name:
raRespWinSize
Description:
Random Access Response Window Size: Random Access Response Window Size parameter defines the window size for the random access response in TTIs.
Range/Step:
2 (0), 3 (1), 4 (2), 5 (3), 6 (4), 7 (5), 8 (6), 10 (7)
Default:
10 (7)
Remark:
raRespWinSize: The start of this UE timer is the subframe number containing the end of the preamble + 3 subframes => 2 ms after this subframe. The UE
must receive the RAR within this window otherwise it assumes the RACH procedure as failed.
2.2.2 Maximum Content Resolution Timer Name:
raContResoT
Description:
Maximum Content Resolution Timer: The Maximum Content Resolution Timer parameter defines the maximum amount of time allowed for contention resolution.
Range/Step:
8ms (0), 16ms (1), 24ms (2), 32ms (3), 40ms (4), 48ms (5), 56ms (6), 64ms (7)
Default:
32ms (3)
Remark:
raContResoT: Trigger for this UE Timer is the transmission of the MSG 3. In case the UE does not receive the MSG 4 within this time window it assumes that the contention resolution fails. In this case the UE will restart the RACH procedure.
Remark:
This Parameter is deleted for RL10/RL15TD and later releases
Name:
raBackoff
Description:
Random Access Backoff: The Random Access Backoff parameter defines the backoff in TTIs that should be applied if a random access fails.
Range/Step:
2 (0), 5 (1), 10 (2), 20 (3), 50 (4), 100 (5), 200 (6), 500 (7), 1000 (8):
Default:
-
Remark:
According to SFS (RL2 from January 2010 - SFS-RL2_683): If the MAC entity detects overload/contention in access to RA preambles, it shall include a backoff indicator into RA Response message to force backoff parameter value update in UEs. The backoff indicator shall be included into succeeding RA Response messages until the contention situation is resolved. The criteria for detection of overload/contention are FFS; in the meantime, the WA is that the backoff indicator value will be statically configured using the raBackoffSize management parameter. (SLS-RL2_1060). If the backoff indicator value is zero, then the backoff indicator subheader will not be signaled to the UE. Coding of the backoff indicator is detailed in 3GPP-36.321
LTE - Random Access | 01.09.2010
2.2.3 Random Access Backoff
22
2.2.4 Preamble Transmission Maximum Name:
preambTxMax
Description:
Preamble Transmission Maximum: The parameter Preamble Transmission Maximum defines the maximum number of random access transmissions. Note: The values n50, n100 and n200 should not be used.
Range/Step:
3 (0), 4 (1), 5 (2), 6 (3), 7 (4), 8 (5), 10 (6), 20 (7), 50 (8), 100 (9), 200 (10)
Default:
8 (5)
LTE - Random Access | 01.09.2010
2.2.5 C-RNTI Reuse Timer
23
Name:
raCrntiReuseT
Description:
C-RNTI Reuse Timer: On receiving information that a UE has gone to RRC_IDLE, the eNB is not able to re-allocate the C-RNTI of an UE to another UE until this time has elapsed. This parameter is a vendor-specific parameter.
Range/Step:
1...60 s, step 1 s
Default:
20 s
2.3 Preamble / Preamble Groups 2.3.1 Overview Overview Preamble Groups
RA preamble selection
Dedicated RA preambles
Yes
Preambel signaled to UE (e.g. HO..)
# of RA preambles for Group A [raPreGrASize / Default = 32]
Total # of non dedicated RA preambles [raNondedPreamb / Default = 40]
Preamble Group B
Preamble Group B
Continue with RA procedure
Non dedicated RA preambles
Total number of preambles = 64
Use the signaled preamble (dedicated preamble)
NO
MSG 3 has been transmitted
Yes
NO
Select the same group of RA preambles as used for the first attempt
Continue with RA procedure Preamble Group B exists And If UE needs to send a large MSG3 AND its measured path loss is less than Pmax PREAMBLE_INITIAL_RECEIVED_TARGET_POWER - DELTA_PREAMBLE_MSG3 – messagePowerOffsetGroupB [raMsgPoffGrB / Default = 10dB]
Yes
Other parameter: - raLargeMcsUl – Default = 5 - raSmallMcsUl – Default = 5 - raLargeVolUl – Default = 512 - raSmallVolUl – Default = 144
Peter Stöckl Network Engineering March 2010
No
Select Preamble from Group B
Select Preamble from Group A
Continue with RA procedure
Continue with RA procedure
Name:
raNondedPreamb
Description:
Number Of Random Access Preambles: This parameter determines the total number of non dedicated RA preambles that UE can select from (i.e. for contention based RA). The minimum cannot be zero.
Range/Step:
4 (0), 8 (1), 12 (2), 16 (3), 20 (4), 24 (5), 28 (6), 32 (7), 36 (8), 40 (9), 44 (10), 48 (11), 52 (12), 56 (13), 60 (14), 64 (15)
Default:
40 (9)
LTE - Random Access | 01.09.2010
2.3.2 Number of RA Preambles
24
2.3.3 RA Preambles Group A Size Name:
raPreGrASize
Description:
Random Access Preambles Group A Size: Defines the size of the Random Access Preambles Group A.
Range/Step:
4 (0), 8 (1), 12 (2), 16 (3), 20 (4), 24 (5), 28 (6), 32 (7), 36 (8), 40 (9), 44 (10), 48 (11), 52 (12), 56 (13), 60 (14)
Default:
32 (7)
2.3.4 RA Message Power Offset for Group B selection Name:
raMsgPoffGrB
Description:
RA Message Power Offset For Group B Selection: Path loss threshold in dB required for selecting one of the two groups of Random Access Preambles. The UE will only use preambles from group B if it needs to send a large Msg3 AND its measured path loss is less than Pmax PREAMBLE_INITIAL_RECEIVED_TARGET_POWER - DELTA_PREAMBLE_MSG3 messagePowerOffsetGroupB (see 36.321 ch 5.1.2)
Range/Step:
-infinity (0), 0 dB (1), 5 dB (2), 8 dB (3), 10 dB (4), 12 dB (5), 15 dB (6), 18 dB (7)
Default:
10 dB (4)
2.4 Message Size Message Coding
LTE - Random Access | 01.09.2010
2.4.1 Large Size RA MCS in UL
25
Name:
raLargeMcsUl
Description:
Large Size Random Access MCS in Uplink: Defines the modulation and coding scheme (MCS) to be used for large size Random Access Message 3 in case of initial access or handover
Range/Step:
0...15, step 1
Default:
5
2.4.2 Large Size RA Data Volume in UL Name:
raLargeVolUl
Description:
Large Size Random Access Data Volume In Uplink: This parameter defines the data volume to be used for large size Random Access Message 3 in the case of an initial access or handover. This parameter is vendor specific.
Range/Step:
216...512 bit, step 8 bit
Default:
512 bit
2.4.3 Samll Size RA MCS in UL Name:
raSmallMcsUl
Description:
Small Size Random Access MCS in Uplink: Defines the modulation and coding scheme (MCS) to be used for the small size Random Access Message 3 in case of UL or DL data arrival. Parameter is vendor specific parameter
Range/Step:
0...15, step 1
Default:
5
2.4.4 Small Size RA Data Volume in UL Name:
raSmallVolUl
Description:
Small Size Random Access Data Volume in Uplink: Defines the data volume to be used for small size Random Access Message 3 in case of UL or DL data arrival.
Range/Step:
56 bits (0), 144 bits (1), 208 bits (2), 256 bits (3)
Default:
144 bits (1)
Name:
maxCrRa4Dl
Description:
Maximum Coderate For Random Access Messge 4: The parameter defines the maximum coderate for Random Access Procedure messages 4 (SRB0 message) This maximum coderate is taken into account during PDSCH scheduling.
Range/Step:
0.05...0.5, step 0.01
Default:
0.12
2.4.6 Max Coderate for RA MSG2 (RAR)
LTE - Random Access | 01.09.2010
2.4.5 Max Coderate for RA MSG4
26
Name:
maxCrRaDl
Description:
Maximum Coderate For Random Access Messge 2: The parameter defines the maximum coderate for Random Access Procedure messages 2 (RA response) This maximum coderate is taken into account during PDSCH scheduling.
Range/Step:
0.05...0.5, step 0.01
Default:
0.12
2.4.7 Max Number of MSG3 HARQ Transmissions Name:
harqMaxMsg3
Description:
Maximum Number Of Message 3 HARQ Transmissions: Indicates the maximum number of HARQ transmissions used for Message 3 of the contention based random access procedure.
Range/Step:
1...8, step 1
Default:
5
2.4.8 PDCCH Aggregation Level for RA MSG4 Name:
pdcchAggMsg4
Description:
PDCCH Aggregation For RA Msg4: The parameter defines the reserved number of Control Channel Elements (CCEs) for dedicated Random Access Message 4 assingment on PDCCH.
Range/Step:
4...8, step 4
Default:
4
LTE - Random Access | 01.09.2010
2.4.9 PDCCH Aggregation Level for Preamble assignments Name: pdcchAggPreamb
27
Description:
PDCCH Aggregation Level For Preamble Assignments: The parameter defines aggregation level by means of control channel elements (CCEs) for preamble assignments on PDCCH. The preamble assignment is message 0 sent during the non-contention based Random Access procedure in the case of DL data arrival during UL out-of-sync.
Range/Step:
4...8, step 4
Default:
4
2.4.10 PDCCH Aggregation Level for RAR Name:
pdcchAggRaresp
Description
PDCCH Aggregation For Random Access Response Message: PDCCH Aggregation for Random Access Response Message. Defines how many CCEs are used for one PDCCH.
Range/Step:
4...8, step 4
Default:
4
2.5 RACH Power 2.5.1 Overview Power Ramping •
Open loop power control together with optional power ramp-up is used during the random access process at the beginning of the connection until more accurate control information is available.
•
PPRACH = min {Pmax, Preamble_Initial_Received_Target_Power + Path Loss}
•
The open loop power control is performed by the UE, based on received information transmitted on system information block in broadcast channel (BCH) and the measured path loss in downlink
•
The eNB broadcasts the initial transmission power level and the power step to the UE in the BCH (Broadcast channel)
•
The UE sets the initial transmission power in the first preamble and waits for the UL grant on PDCCH. If not acknowledged, the MS increases the preamble transmission power by a specified power offset step.
Name:
ulpcIniPrePwr
Description:
Preamble Initial Received Target Power: The Preamble Initial Received Target Power parameter defines the initial power for Random Access Preamble transmission.
Range/Step:
-120 dBm (0), -118 dBm (1), -116 dBm (2), -114 dBm (3), -112 dBm (4), -110 dBm (5), -108 dBm (6), -106 dBm (7), -104 dBm (8), -102 dBm (9), -100 dBm (10), -98 dBm (11), -96 dBm (12), -94 dBm (13), -92 dBm (14), -90 dBm (15):
Default:
-104 dBm (8)
LTE - Random Access | 01.09.2010
2.5.2 Preamble Initial Received Target Power
28
2.5.3 RA Power Ramping Setup Remark:
This Parameter is deleted for RL10/RL15TD and later releases
Name:
raPowRampSetup
Description:
RA Power Ramping Setup: Power Ramping Setup - WA in 3GPP
Range/Step:
0...1, step 1
Default:
-
2.5.4 Power ramping Step for RA Name:
prachPwrRamp
Description:
Power Ramping Step: The Power Ramping Step Size parameter defines the power increment step size for Random Access Preamble transmission.
Range/Step:
0dB (0), 2dB (1), 4dB (2), 6dB (3)
Default:
2dB (1)
LTE - Random Access | 01.09.2010
2.5.5 TPC Command in RAR
29
Name:
ulpcRarespTpc
Description:
TPC Command In Random Access Response: TPC command indicated in the random access response related to Random Access message 3 or 1st scheduled uplink transmission.
Range/Step:
-6...8 dB, step 2 dB:
Default:
-
3 Type of RACH procedures 3.1 Contention Based 3.1.1 Overview Contention based Radom Access Procedure
UE
eNB Random Access Preamble ( on PRACH)
( with embedded1- bit indication for L 2/L 3 message size)
1
Random Access Response ( on PDCCH+ PDSCH) ( Timing Adjustment,C- RNTI, UL grant for L2/ 3 message..)
2
L2/L 3 message (
PUSCH transmission including contentin resolution identity)
3
Contention resolution Message 4
LTE - Random Access | 01.09.2010
Peter Stöckl Network Engineering March 2010
30
31
UL @ eNB
UL @ UE
Propagation RTT
DL @ UE
Propagation delay
DL @ eNB
RACH Preamble RX @ eNB
RACH Preamble TX @ UE
RAR RX @ UE
MSG3 RX @ eNB
MSG3 TX @ UE
5TT – Propagation RTT Minimum delay for sending MSG3 after RX of RAR @ UE
5 TTI
MSG4 RX @ UE => RA procedure successful
MSG4 TX @ eNB
Peter Stöckl Network Engineering March 2010
MACCountResoTimer [raContResT - default: 32ms]
After TX or re-TX of MSG3 @ UE; UE start CR timer / If UE does not receive MSG4 addressed to its C-RNTI when timer expires, UE considers contention resolution not successful / or if UE receives a MSG4 with an UE’s identity different from its own / in case RA procedure fails then UE should wait „raBackoff“ until starting new RA procedure)
Propagation RTT
RAR Window Size / raRespWinSize [default 10 TTI = 10ms]
1 TTI [1 ms]
Contention Based RA Procedure without problems
Start of RAR Window = Subframe containing the end of the preamble + 3 subframes (or in other words 2 ms after the end of the subframe containing the end of the preamble
RAR TX @ eNB (e.g. 4 ms after RX of preamble)
LTE - Random Access | 01.09.2010
3.1.2 Process without problems
X
1
2
3
4
4
5
8
9
0
RAR TX @ eNB (e.g. 4 ms after RX of preamble)
7
1
2
6
X 7
8
9
0
Or (b) PDSCH part of RAR @ UE not decoded in case PDCCH successful decoded
1
2
3
RACH Preamble not received @ UE [first possibility]
4
3
4
1 TTI [1 ms]
RACH Preamble TX @ UE Initial Power for Preamble (open loop power control) PRACH = min{PMAX; ulpcIniPrePwr + PL} ulpcIniPrePwr = Preamble initial received target power [Default: -104dBm] PL = path loss measured by UE from RS-Signals
3
6
RAR Window Size / raRespWinSize [default 10 TTI = 10ms]
5
Either (a) PDCCH part of RAR @ UE not decoded [Aggregation level of RAR PDCCH defined by pdcchAggRaresp]
2
LTE - Random Access | 01.09.2010
UL @ eNB
UL @ UE
Propagation RTT
DL @ UE
Propagation delay
DL @ eNB
1
Sub-Frame
Depicted example: PrachConfIndex = 3 (Default)
8
9
6
0
1
2
7
8
3
9
0
1
2
3
min 4ms min delay after RAR window for retransmission in case of no RAR detection
min 3ms min delay after RAR window for retransmission in case of no RAR detection
7
4
4
Sub-Frame 5
5
Peter Stöckl Network Engineering March 2010
Power for Preamble retransmission PRACH-Retrans = min{PMAX; PRACH-Previous + prachPwrRamp} prachPwrRamp [Default: 2dB] Retransmission unitil maximum amount of preamble transmissions is reached: preambTxMax [default = 8]
5
6
RACH Preamble RE-TX @ UE [only in Sub-Frame # 1 as prachconfIndex = 3]
5
Contention Based RA Procedure with problems -> Preamble detection or RAR detection/decoding
3.1.3 Process with problems Preamble/RAR detection/decoding
32
33
UL @ eNB
UL @ UE
Propagation RTT
DL @ UE
Propagation delay
DL @ eNB
RACH Preamble RX @ eNB
RACH Preamble TX @ UE
RAR RX @ UE
MSG3 RX @ eNB not correctly decoded
MSG3 TX @ UE
5TT – Propagation RTT Minimum delay for sending MSG3 after RX of RAR @ UE
5 TTI MSG 3 NACK
X
Propagation RTT
RAR Window Size / raRespWinSize [default 10 TTI = 10ms]
Start of RAR Window Size = Subframe containing the end of the preamble + 3 subframes (or in other words 2 ms after the end of the subframe containing the end of the preamble
1 TTI [1 ms]
Restart of raContResT
Parameter ‚ Maximum number of message 3 HARQ retransmission’ defines the max number of HARQ transmission for MSG3 [parmeter: harqMaxMsg3 / default = 5]
Peter Stöckl Network Engineering March 2010
MACCountResoTimer [raContResT - default: 32ms]
MSG 3 first retransmission
Contention Based RA Procedure with problems -> MSG3 retransmissions
RAR TX @ eNB (e.g. 4 ms after RX of preamble)
LTE - Random Access | 01.09.2010
3.1.4 Process with problems MSG3 problems
3.2 Contention Free 3.2.1 Overview Contention Free Random Access Procedure
UE
eNB
Random Access Preamble Assignment 0 Random Access Preamble ( on PRACH)
1
Random Access Respoonse ( on PDCCH+ PDSCH)
2
For new downlink data or HO eNB has the option of allocating a dedicated signature to a UE => contention free access is possible => faster than contention based and therefore better for time-critical procedures like HO
LTE - Random Access | 01.09.2010
Peter Stöckl Network Engineering March 2010
34
3.2.2 Process
Contention free Random Access procedure in case of handover
In principle the contention free RA procedure is equal to the contention based RA procedure however: uses dedicated preambles and ends after the RAR
If no dedicated preambles are available eNB shall command contention based RA procedure [done by omitting the preamble]
Source cell shall select a free dedicated RA preamble and shall signal the selected RA preamble together with the related C-RNTI for this HO to the UE in the Handover Command Message
UE shall access the new cell by using this dedicated preamble [Timing: PrachConfIndex => default = 3 => one PRACH type 0 per radio frame / always in sub-frame 1] [Power: PRACH = min{PMAX; ulpcIniPrePwr + PL} ulpcIniPrePwr = Preamble initial received target power [Default: 104dBm] PL = path loss measured by UE from RS-Signals {referenceSignalPower transmitted in SIB2 subtable 1}]
After transmission of Preamble UE expects the RA response (RAR) from the eNB with the RAR Window: Start of RAR Window: Subframe containing the end of the preamble + 3 subframes Size of RAR Window: raRespWinSize [default 10 TTI = 10ms]
Yes
End of contention free random access procedure
LTE - Random Access | 01.09.2010
The RAR is typically transmitted by the eNB app 4TTI after the receiving the preamble
35
RAR received by UE
No RAR during RAR Window
Min delay after RAR window for retransmission of preamble is 3 ms
No
RAR detection problem
Detect PDCCH part of RAR but problems with decoding PDSCH part of RAR
Min delay for retransmission of preamble is increased to 4 ms
Retransmission of preamble with increased power. Peter Stöckl Network Engineering March 2010
unitil maximum amount of preamble transmissions is reached: preambTxMax [default = 8] PRACH-Retrans = min{PMAX; PRACH-Previous + prachPwrRamp} prachPwrRamp [Default: 2dB]
4 RACH/PRACH planning/dimensioning 4.1 Recommendation PRACHs from neighboring cells can be separated: •
by CDMA -> PRACH cyclic shift. (The larger the cell is, the longer is the required zero correlation value. Note that the processing power is directly scaled with the number of root sequences)
•
by frequency domain -> PRACH frequency Offset (PRACH could be varied in frequency domain, however avoid fragmentation of PUSCH area -> therefore place the PRACH next to the PUCCH area)
•
by Time domain, -> PRACH configuration Index (the time domain is almost deployable)
4.2 Preamble Selection 4.2.1 Normal Cell Select an appropriate preamble format based on the cell range. See table below:
burst format (preamble format)
subframes
0
max. delay spread (due to CP) [µs]
max. cell radius (due to guard and CP) [km]
CP [µs]
PRE [µs]
Guard [µs]
max. cell radius (due to guard) [km]
1
103.1
800.0
96.9
14.53
6.3
97.9
14.69
14.53
1
2
684.4
800.0
515.6
77.34
168.8
679.2
101.88
77.34
2
2
203.1
1600.0
196.9
29.53
6.3
197.9
29.69
29.53
3
3
684.4
1600.0
715.6
107.34
-31.3
679.2
101.88
101.88
max. cell radius (due to CP considering 5,2 us delay spread) [µs] [km]
Example: Assume a cell range of 37km. So an appropriate preamble format could be format 1 or format 3. As there is no need for preamble format 3; format 1 should be chosen (requires less resources than format 3).
LTE - Random Access | 01.09.2010
First:
36
Second:
Select zero correlation or NCS Index out of the table below:
NCs Config.
NCS
sign. per root seq.
1
13
64
2
15
3
#root seq.
no delay spread
delay spread = 5,2 us
With preamble guard
us
km
Us
km
Guard
NCS
us
km
us
km
1
12.4
1.86
7.2
1.08
2.25
10.75
10.3
1.54
5.1
0.76
55
2
14.3
2.15
9.1
1.37
2.25
12.75
12.2
1.82
7.0
1.04
18
46
2
17.2
2.57
12.0
1.79
2.25
15.75
15.0
2.25
9.8
1.47
4
22
38
2
21.0
3.15
15.8
2.37
2.25
19.75
18.8
2.82
13.6
2.04
5
26
32
2
24.8
3.72
19.6
2.94
2.25
23.75
22.6
3.40
17.4
2.62
6
32
26
3
30.5
4.58
25.3
3.80
2.25
29.75
28.4
4.26
23.2
3.48
7
38
22
3
36.2
5.44
31.0
4.66
2.25
35.75
34.1
5.11
28.9
4.33
8
46
18
4
43.9
6.58
38.7
5.80
2.25
43.75
41.7
6.26
36.5
5.48
9
59
14
5
56.3
8.44
51.1
7.66
2.25
56.75
54.1
8.12
48.9
7.34
10
76
11
6
72.5
10.87
67.3
10.09
2.25
73.75
70.3
10.55
65.1
9.77
11
93
9
8
88.7
13.30
83.5
12.52
2.25
90.75
86.5
12.98
81.3
12.20
12
119
7
10
113.5
17.02
108.3
16.24
2.25
116.75
111.3
16.70
106.1
15.92
13
167
5
13
159.2
23.89
154.0
23.11
2.25
164.75
157.1
23.56
151.9
22.78
14
279
3
22
266.0
39.90
260.8
39.12
2.25
276.75
263.9
39.58
258.7
38.80
15
419
2
32
399.5
59.93
394.3
59.15
2.25
416.75
397.4
59.61
392.2
58.83
0
839
1
64
800.0
120.00
794.8
119.22
2.25
836.75
797.9
119.68
792.7
118.90
LTE - Random Access | 01.09.2010
Example: In the above given example for a cell range of 37km the best choice for NCS would be 14 as it allows cell ranges with 38.8km. Therefore a lower index would not meet the distance requirements and choosing a higher index will require more root sequences and therefore higher processing power. As given in the above depicted table 3 signatures per root sequence are available and therefore 22 root sequences are needed to fulfill the requirement of 64 sequences.
37
Third:
Select 22 successive root sequences out of the table given in 2.13. Example: e.g. Select logical root sequence numbers 0-21.
4.2.2 High Speed Cell Out of the below given table, it can be seen that the maximum cell range for a high speed cell is 32.8 km. (limited by the cyclic shift sets and not by the preambles)
NCs Config.
NCS
sign. per root seq.
0
15
18
1
18
2
#root seq.
no delay spread
delay spread = 5,2 us
With preamble guard
us
km
Us
km
Guard
NCS
us
km
us
km
4
14.3
2.15
9.1
1.37
2.25
12.75
12.2
1.82
7.0
1.04
15
6
17.2
2.57
12.0
1.79
2.25
15.75
15.0
2.25
9.8
1.47
22
12
6
21.0
3.15
15.8
2.37
2.25
19.75
18.8
2.82
13.6
2.04
3
26
10
8
24.8
3.72
19.6
2.94
2.25
23.75
22.6
3.40
17.4
2.62
4
32
8
9
30.5
4.58
25.3
3.80
2.25
29.75
28.4
4.26
23.2
3.48
5
38
7
11
36.2
5.44
31.0
4.66
2.25
35.75
34.1
5.11
28.9
4.33
6
46
6
14
43.9
6.58
38.7
5.80
2.25
43.75
41.7
6.26
36.5
5.48
7
55
4
17
52.4
7.87
47.2
7.09
2.25
52.75
50.3
7.54
45.1
6.76
8
68
4
20
64.8
9.73
59.6
8.95
2.25
65.75
62.7
9.40
57.5
8.62
9
82
3
26
78.2
11.73
73.0
10.95
2.25
79.75
76.0
11.41
70.8
10.63
10
100
2
32
95.4
14.30
90.2
13.52
2.25
97.75
93.2
13.98
88.0
13.20
11
128
2
44
122.1
18.31
116.9
17.53
2.25
125.75
119.9
17.99
114.7
17.21
12
158
1
64
150.7
22.60
145.5
21.82
2.25
155.75
148.5
22.28
143.3
21.50
13
202
1
64
192.6
28.89
187.4
28.11
2.25
199.75
190.5
28.57
185.3
27.79
14
237
1
64
226.0
33.90
220.8
33.12
2.25
234.75
223.8
33.58
218.6
32.80
Out of the below given table the logical root sequence number should be selected.
CM group
Subgroup No.
NCS (high speed)
Logical root sequence number
Low
0
-
0–23
Physical root sequence index u (in increasing order of the corresponding logical sequence number) Preamble formats 0-3 129, 710, 140, 699, 120, 719, 210, 629, 168, 671, 84, 755, 105, 734, 93, 746, 70, 769, 60,
LTE - Random Access | 01.09.2010
Example: For this example assume a cell range of 20km radius. For 20 km cell range preamble format 1 or 2 could be selected. As format 2 is not supported by NSN at the moment, and the only benefit of format 2 would be to be more robust as it requires lower SINR, format 1 is chosen. Out of the above given table for this example NCS index 12 would be the best choice. Anyhow as given in this table with index 12 already 64 root sequences are required.
38
CM group
Subgroup No.
NCS (high speed)
Logical root sequence number
Physical root sequence index u (in increasing order of the corresponding logical sequence number) Preamble formats 0-3 779, 2, 837, 1, 838
1
15
24–29
56, 783, 112, 727, 148, 691
2
18
30–35
80, 759, 42, 797, 40, 799
3
22
36–41
35, 804, 73, 766, 146, 693
4
26
42–51
31, 808, 28, 811, 30, 809, 27, 812, 29, 810
5
32
52–63
24, 815, 48, 791, 68, 771, 74, 765, 178, 661, 136, 703
6
38
64–75
86, 753, 78, 761, 43, 796, 39, 800, 20, 819, 21, 818
7
46
76–89
95, 744, 202, 637, 190, 649, 181, 658, 137, 702, 125, 714, 151, 688
8
55
90–115
217, 622, 128, 711, 142, 697, 122, 717, 203, 636, 118, 721, 110, 729, 89, 750, 103, 736, 61, 778, 55, 784, 15, 824, 14, 825
9
68
116–135
12, 827, 23, 816, 34, 805, 37, 802, 46, 793, 207, 632, 179, 660, 145, 694, 130, 709, 223, 616
136–167
228, 611, 227, 612, 132, 707, 133, 706, 143, 696, 135, 704, 161, 678, 201, 638, 173, 666, 106, 733, 83, 756, 91, 748, 66, 773, 53, 786, 10, 829, 9, 830
168–203
7, 832, 8, 831, 16, 823, 47, 792, 64, 775, 57, 782, 104, 735, 101, 738, 108, 731, 208, 631, 184, 655, 197, 642, 191, 648, 121, 718, 141, 698, 149, 690, 216, 623, 218, 621
204–263
152, 687, 144, 695, 134, 705, 138, 701, 199, 640, 162, 677, 176, 663, 119, 720, 158, 681, 164, 675, 174, 665, 171, 668, 170, 669, 87, 752, 169, 670, 88, 751, 107, 732, 81, 758, 82, 757, 100, 739, 98, 741, 71, 768, 59, 780, 65, 774, 50, 789, 49, 790, 26, 813, 17, 822, 13, 826, 6, 833
264–327
5, 834, 33, 806, 51, 788, 75, 764, 99, 740, 96, 743, 97, 742, 166, 673, 172, 667, 175, 664, 187, 652, 163, 676, 185, 654, 200, 639, 114, 725, 189, 650, 115, 724, 194, 645, 195, 644, 192, 647, 182, 657, 157, 682, 156, 683, 211, 628, 154, 685, 123, 716, 139, 700, 212, 627, 153,
10
LTE - Random Access | 01.09.2010
11
39
12
13
82
100
128
158
CM group
Subgroup No.
NCS (high speed)
Logical root sequence number
Physical root sequence index u (in increasing order of the corresponding logical sequence number) Preamble formats 0-3
14
15
16
17
202
237
237
202
328–383
225, 614, 224, 615, 221, 618, 220, 619, 127, 712, 147, 692, 124, 715, 193, 646, 205, 634, 206, 633, 116, 723, 160, 679, 186, 653, 167, 672, 79, 760, 85, 754, 77, 762, 92, 747, 58, 781, 62, 777, 69, 770, 54, 785, 36, 803, 32, 807, 25, 814, 18, 821, 11, 828, 4, 835
384–455
3, 836, 19, 820, 22, 817, 41, 798, 38, 801, 44, 795, 52, 787, 45, 794, 63, 776, 67, 772, 72, 767, 76, 763, 94, 745, 102, 737, 90, 749, 109, 730, 165, 674, 111, 728, 209, 630, 204, 635, 117, 722, 188, 651, 159, 680, 198, 641, 113, 726, 183, 656, 180, 659, 177, 662, 196, 643, 155, 684, 214, 625, 126, 713, 131, 708, 219, 620, 222, 617, 226, 613
456–513
230, 609, 232, 607, 262, 577, 252, 587, 418, 421, 416, 423, 413, 426, 411, 428, 376, 463, 395, 444, 283, 556, 285, 554, 379, 460, 390, 449, 363, 476, 384, 455, 388, 451, 386, 453, 361, 478, 387, 452, 360, 479, 310, 529, 354, 485, 328, 511, 315, 524, 337, 502, 349, 490, 335, 504, 324, 515
514–561
323, 516, 320, 519, 334, 505, 359, 480, 295, 544, 385, 454, 292, 547, 291, 548, 381, 458, 399, 440, 380, 459, 397, 442, 369, 470, 377, 462, 410, 429, 407, 432, 281, 558, 414, 425, 247, 592, 277, 562, 271, 568, 272, 567, 264, 575, 259, 580
562–629
237, 602, 239, 600, 244, 595, 243, 596, 275, 564, 278, 561, 250, 589, 246, 593, 417, 422, 248, 591, 394, 445, 393, 446, 370, 469, 365, 474, 300, 539, 299, 540, 364, 475, 362, 477, 298, 541, 312, 527, 313, 526, 314, 525, 353, 486, 352, 487, 343, 496, 327, 512, 350, 489, 326, 513, 319, 520, 332, 507, 333, 506, 348, 491, 347, 492, 322, 517
630–659
330, 509, 338, 501, 341, 498, 340, 499, 342, 497, 301, 538, 366, 473, 401, 438, 371, 468, 408, 431, 375, 464, 249, 590, 269, 570, 238, 601, 234, 605
High
18
19
158
128
LTE - Random Access | 01.09.2010
686, 213, 626, 215, 624, 150, 689
40
CM group
Subgroup No.
20
LTE - Random Access | 01.09.2010
21
41
NCS (high speed)
100
82
Logical root sequence number
Physical root sequence index u (in increasing order of the corresponding logical sequence number) Preamble formats 0-3
660–707
257, 582, 273, 566, 255, 584, 254, 585, 245, 594, 251, 588, 412, 427, 372, 467, 282, 557, 403, 436, 396, 443, 392, 447, 391, 448, 382, 457, 389, 450, 294, 545, 297, 542, 311, 528, 344, 495, 345, 494, 318, 521, 331, 508, 325, 514, 321, 518
708–729
346, 493, 339, 500, 351, 488, 306, 533, 289, 550, 400, 439, 378, 461, 374, 465, 415, 424, 270, 569, 241, 598
22
68
730–751
231, 608, 260, 579, 268, 571, 276, 563, 409, 430, 398, 441, 290, 549, 304, 535, 308, 531, 358, 481, 316, 523
23
55
752–765
293, 546, 288, 551, 284, 555, 368, 471, 253, 586, 256, 583, 263, 576
24
46
766–777
242, 597, 274, 565, 402, 437, 383, 456, 357, 482, 329, 510
25
38
778–789
317, 522, 307, 532, 286, 553, 287, 552, 266, 573, 261, 578
26
32
790–795
236, 603, 303, 536, 356, 483
27
26
796–803
355, 484, 405, 434, 404, 435, 406, 433
28
22
804–809
235, 604, 267, 572, 302, 537
29
18
810–815
309, 530, 265, 574, 233, 606
30
15
816–819
367, 472, 296, 543
31
-
820–837
336, 503, 305, 534, 373, 466, 280, 559, 279, 560, 419, 420, 240, 599, 258, 581, 229, 610
Example: For the above given example the 64 required root sequences can be selected out of the logical root sequence numbers from 264 up to 629 since for those the possible NCS restricted index is at least 158.
5 PM-Counter 5.1 Number of available RACH channels Title
Number of available RACH channels
Mtype
Cell Load
Shortname
RACH_CHANNELS
Description
This measurement provides the minimum, maximum and mean number of reserved and available RACH channels. Reserved RACH channels are those channels that can be used for random access procedure. Available means that they must be in operational state ‘enabled’ and in administrative state ‘unlocked’ or ‘shutting down’
Number of Counters
3
Counters
Minimum number of available RACH channels. Maximum number of available RACH channels. Mean number of available RACH channels.
Adm. Object
eNB
Measured Object
Cell
Counter Type
Real
Counter Unit
None
Trigger Event
This measurement is triggered by the creation/deletion of RACH channels as well as each state change of those channels
Remark
None
History
Introduced in RL09
Title
Number of RACH setup attemps
Mtype
Cell Load
Shortname
RACH_SETUP_ATT
Description
This measurement provides the number of RACH setup attempts. Both RA preamble groups shall be monitored.
Number of Counters
2
Counters
Number of RACH setup attempts for small size messages. Number of RACH setup attempts for large size messagess.
Adm. Object
eNB
LTE - Random Access | 01.09.2010
5.2 RACH setup attempts
42
Measured Object
Cell
Counter Type
Integer
Counter Unit
None
Trigger Event
Receipt of a RA preamble sent by the UE to the eNB 3GPP TS36.321 (RA preamble)
Remark
None
History
Introduced in RL09
LTE - Random Access | 01.09.2010
5.3 RACH setup completions
43
Title
Number of RACH setup completions
Mtype
Cell Load
Shortname
RACH_SETUP_SUCC
Description
This measurement provides the number of RACH setup completions.
Number of Counters
1
Counters
Number of RACH setup completions.
Adm. Object
eNB
Measured Object
Cell
Counter Type
Integer
Counter Unit
None
Trigger Event
Transmission of a RA Response sent from eNB to UE. 3GPP TS36.321 (RA Response)
Remark
If RA Response message consists of information for N (N>1) RA preambles, the measurement is increased by N.
History
Introduced in RL09
5.4 UL PRB utilization per PRACH, PUCCH, PUSCH Title
PRB utilization per channel (UL/DL)
Mtype
Cell Resource
Shortname
PRB_UTIL_CHANNEL
Description
These measurements provide the PRB utilization per physical channel. The reference point is the Service Access Point between MAC and L1. A sum counter allows to calculate the relative utilization of each channel.
Number of Counters
8
Counters
Total PRB used UL PRBs used for PRACH PRBs used for PUCCH PRBs used for PUSCH Total PRB used in DL PRBs used for PBCH
Adm. Object
eNB
Measured Object
Cell
Counter Type
Integer
Counter Unit
None
Trigger Event
Cumulative measurement. Triggered for each scheduling period by an internal trigger.
Remark
3GPP TS32425 v.030, 3GPP TS36314 v.100
History
Introduced in RL10
LTE - Random Access | 01.09.2010
PRBs used for PDCCH PRBs used for PDSCH
44
LTE - Random Access | 01.09.2010
6 References
45
[1]
3GPP TS36.211 V8.8.0 (2009-09) 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Envolved Universal Terrestrial Radio Access (E-UTRAN); Physical Channels and Modulation (Release 8)
[2]
NSN SFS TF LTE SFS Radio Layer 1 (RL1) (FDD & TDD releases)
[3]
NSN SFS (FDD & TDD releases) TF LTE SFS Radio Layer 2 (RL2) [PDCP/RLC/MAC]
[4]
NSN SFS (FDD & TDD releases) RRM LTE SFS eNB Radio Resource Management
[5]
NSN SFS PMO LTE SFS Radio related Performance
[6]
LTE for UMTS OFDMA and SC-FDMA Based Radio Access Harri Holma and Antti Toskala John Wiley & Sons Ltd. – 2009
[7]
LTE – The UMTS Long Term Evolution From Theory to Practice Edited by: Stefania Sesia; Issam Toufik; Matthew Baker John Wiley & Sons Ltd. – 2009
[8]
LTE for 4G Mobile Broadband Air Interface Technologies and Performance Farooq Khan Cambridge University Press, 2009
[9]
NSN Academy Training Documentation for LTE Parameter LTEPAR-Pilot RL09 – January 2010
[10]
NSN NE Enabling RL10 Handouts to session ‘Radio Layer 1 Fundamentals’ January 2010
