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www.huawei.com
Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Um Interface and Radio Channels
Page2Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. Overview
2. Processing of Voice Signal
3. Radio Channel
Page3Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Radio Interface
Another MSC
HLR/AUC
SMC
PSTN ISDN
OMC
MS
Um
MS
A-bis
BSC
A
BTS
MSC/VLR
Page4Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Communication management (CM)Communication management (CM)
Radio resources management (RR)Radio resources management (RR)
Mobility and security management (MM)
Mobility and security management (MM)
Integrated managementIntegrated management
TCH0 TCH1 TCH2 。。 SACCH 。。 TCH23 IDLTCH0 TCH1 TCH2 。。 SACCH 。。 TCH23 IDL
Multiframe
Physical link layer (L1)
Data link layer (L2)
Network application layer (L3)
Hierarchical Structure of Um Interface
RACH BCCH AGCH/PCH SDCCH SACCH TCH FACCH
Page5Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Radio Access Technology
FrequencyTime
Power
FrequencyTime
Power
FrequencyTime
Power
FDMAFDMA
TDMATDMA
CDMACDMA
User
User User
User
User User
User
User
TimeFDMA
Frequency
TDMATime
Frequency
CDMA
Frequency
Time
Code
Page7Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. Overview
2. Processing of Voice Signal
3. Radio Channel
Page8Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Voice Signal Processing
((A/DA/D))
2020 msms
22.8kbit/s22.8kbit/s
13kbit/s13kbit/s8KHz,13bi8KHz,13bitt
33.8kbit/s33.8kbit/s
SegmentationSegmentation Speech codingSpeech coding Channel codingChannel coding
InterleavingInterleaving EncryptionEncryption)) Burst formatting ModulationModulation
Transmission
Voice
Page10Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Speech Coding The Enhance Enhance Full RateFull Rate coding mode is called CELP CELP (Code Excited Linear PredictCode Excited Linear Predict
ive Codingive Coding) The Full RateFull Rate coding mode is called RPE-LTPRPE-LTP (Regular Pulse Excited-Long Term Regular Pulse Excited-Long Term
Prediction). Prediction). The HalfHalf Rate Rate coding mode is called VCELPVCELP ( (Vector-Sum Excited Linear Vector-Sum Excited Linear
PredictionPrediction))
13kbit/s13kbit/s260 bits(FR)260 bits(FR)
112 bits(HR)112 bits(HR)
244 bits(EFR)244 bits(EFR) 12.2kbit/s12.2kbit/s
5.6kbit/s5.6kbit/s
((A/DA/D))
2020 msms
8KHz,13bi8KHz,13bitt
SegmentationSegmentation Speech codingSpeech coding
Voice
Page11Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Channel Coding
13kbit/s13kbit/s260 bits(FR)260 bits(FR)
112 bits(HR)112 bits(HR)
244 bits(EFR)244 bits(EFR) 12.2kbit/s12.2kbit/s
5.6kbit/s5.6kbit/s
((A/DA/D))
2020 msms
8KHz,13bi8KHz,13bitt
SegmentationSegmentation Speech codingSpeech coding
Voice
Channel codingChannel coding
22.8kbit/s22.8kbit/s456bits(FR/EFR)456bits(FR/EFR)228bits(HR)228bits(HR) 11.4kbit/s11.4kbit/s
Block Coder
1:2
Convolutional
Coder
Page12Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
1 2 3 4 5 6 7 8 ... ... 452 453 454 455 4561 2 3 4 5 6 7 8 ... ... 452 453 454 455 456
B
8
16
.
.
.
456
8
16
.
.
.
456
2
10
.
.
.
450
2
10
.
.
.
450
6
14
.
.
.
454
6
14
.
.
.
454
1
9
.
.
.
449
1
9
.
.
.
449
4
12
.
.
.
452
4
12
.
.
.
452
7
15
.
.
.
455
7
15
.
.
.
455
3
11
.
.
.
451
3
11
.
.
.
451
5
13
.
.
.
453
5
13
.
.
.
453
.... ....
B0 B1 B2 B3 B4 B5 B6 B7
{A4,B0} {A5,B1} {A6,B2} {A7,B3} {B4,C0} {B5,C1} {B6,C2} {B7,C3}{A4,B0} {A5,B1} {A6,B2} {A7,B3} {B4,C0} {B5,C1} {B6,C2} {B7,C3}
First interleaving:
Second interleaving:
Interleaving
Page14Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Voice Burst
Tail Tail bitbit
Tail Tail bitbit
Guard Guard periodperiodDatDat
aaDataData Training sequenceTraining sequence
57 encrypted bits57 encrypted bits 33bitsbits 8.25 bits8.25 bits26 bits26 bits133
bitsbits 57 encrypted bits57 encrypted bits 1
((A/DA/D))
2020 msms
22.8kbit/s22.8kbit/s
13kbit/13kbit/ss8KHz,13bit8KHz,13bit
33.8kbit/33.8kbit/ss
SegmentationSegmentation Speech codingSpeech coding Channel codingChannel coding
InterleavingInterleaving EncryptionEncryption)) Burst formatting ModulationModulation
Transmission
Voice
Page15Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Voice Signal Processing
33.8 kbit/s
22.8 kbit/s
13 kbit/s
8 kHz13 bits
Transmitting part
Receiving part
Speaker
ReceiverDemodulator
Adaptive Equalization
De-cipheringDe-interleaving
Channel decoding
Speech decoding
D/A-conversion
TransmitterModulator
Burst formattingCiphering
Interleaving
Channel coding
Speech codingSegmentation
A/D-conversion
Microphone
13 kbit/s
Transmitting part
Receiving part
TransmitterModulator
Burst formattingCiphering
Interleaving
Channel coding
D/D-conversion
8 kHz8 bits64 kbit/s PCM
ReceiverDemodulator
Adaptive Equalization
De-cipheringDe-interleaving
Channel Decoding
GSM Network
Mobile equipment
Page16Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Transmission delay t
Transmission delay t
TA
The mobile phone should
send the signal in advance!!
Timing Advance (TA)
Page18Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Frequency HoppingFrequency
f 0
Frame
f 1
f 2
f 3
f 4
Time
Page20Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Prolong battery life and reduce interference
DTX
DTX: Discontinuous Transmission Shut off the transmission at voice intervals; Only transmit SID frames’ The transcoder at the RX terminal produces comfortable noise.
VAD: Voice Activity Detection Implemented by the transcoder.
Page22Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Power Control Prolong battery life Reduce network interference Include both uplink power control and downlink power control Level and quality are taken into account BSC or BTS is the final adjudicator
BCCH Carrier is not involved in power control.
Time
Signal level
Target level value:e.g. -85 dm
Page23Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Contents
1. Overview
2. Processing of Voice Signal
3. Radio Channel
Page24Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Frequency
200kHz
15/26ms
BP
Slit
Time
Frame and Channel
Page25Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
32107654321
Physical Channel of Logical Channel
0
differentmessage
types
Logical channel
Physical Channel
Logical channel
Logical channel
Logical channelLogical channel
TDMA FRAME
200K
577 s
Page26Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
8bit 41 synchronous bits
36 encrypted bits
3bit 68.25bit
Tail bit Tail bit Guard intervalData
Guard interval
3bit 142bit 3bit 8.25bit
Tail bit Tail bitData
3bit 39 encrypted bits
39 encrypted bits
3bit 8.25bit
Tail bit Tail bit Guard intervalDataData
Burst
64 synchronous bits
• Access burst (AB): Used in MS initial access
• Frequency correction burst (FB): Used in frequency synchronization between MS and BTS
• Synchronous burst (SB): Used in timing synchronization between MS and BTS
Page27Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
3bit 142 modulation bits 3bit 8.25bit
Tail bit Tail bit Guard interval
Burst
3bit 57 encrypted bits 57 encrypted bits 3bit 8.25bit
Tail bit Tail bit Guard intervalDataData
26bit1 1
Training sequence
Frame stealing flag
Normal burst (NB)
Used to carry the information of the traffic channel and the control
channel except for RACH
Dummy burst (DB)
Used in transmission of filling frames by BTS at timeslots when there is no information delivered
Page28Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Broadcast control channel (BCH)
Control channelCommon control channel (CCCH)
Voice channel(TCH)
FCCH SCH BCCH TCH/FAGCH RACH SDCCH FACCH
SACCH
TCH/HPCH
Common channel (CCH)
Dedicated channel (DCH)
Logical channel
Logical Channel Type
GSM900 and DCS1800 have the same logical channel category
(system information)
Page29Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
FCCH
SCH
BCCH
PCH
AGCH
BCCH
CCCH
Common Channel
SDCCH
SACCH
FACCH
TCH/F
TCH/H
DCCH
TCH
Dedicated Channel
Downlink Logical Channel
Page31Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
RACH CCCH
Common channel
SDCCH
SACCH
FACCH
TCH/F
TCH/H
DCCH
TCH
Dedicated channel
Uplink Logical Channel
Page33Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Use of Logical Channels
FCCH
Allocate signaling channel
Power-on Search for frequency correction burst
Search for synchronous burst
Listen to the system information
Monitor paging message
Send access burst
Set up the call
Allocate voice channel
Conversation
Release the call
Idle mode
SCH
BCCH
PCH
RACH
AGCH
SDCCH
SDCCH
TCH
FACCH
Dedicated mode
Idle mode
Page34Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
26-frame multi-frameTCH/F+FACCH/F+SACCH/F (full-rate TCH)
TCH/H+FACCH/H+SACCH/H (half-rate TCH)
51-frames multi-frameFCCH+SCH+BCCH+CCCH (main BCCH)
FCCH+SCH+BCCH+CCCH+SDCCH/4+SACCH/4 (combined BCCH)
BCCH+CCCH (extended BCCH)
SDCCH/8+SACCH/8 (main SDCCH)
Physical Combination of Logical Channel
Page35Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Structure of Main BCCH1 multi-frame (51TDMA Frames) 235.38ms Downlink
Group Group1 Group2
Group3,
4
(same
as
Group2)
Grpup5
Channel F S BX4 CX4 F S CX4 CX4 …… F S CX4 CX4 I
Frame
Numbe
r
0 1 2-5 6-9 101
1
12-
15
16-
1920-39
4
0
4
1
42-
45
46-
4950
1 multi-frame (51TDMA Frames) 235.38ms Uplink
Channe
lR R R R R R R R R R R R R R……R R R R R
Frame
Numbe
r
0 1 2 3 4 5 6 7 8 9 10 11 12 13-46 474
8
4
9
5
0
F:FCCH; S:SCH; B:BCCH; C:CCCH; R:RACH; I:IDLE
Page36Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Structure of Combined BCCH
1 multi-frame (51TDMA Frames) 235.38ms Downlink
Group Group1 Group2 Group3 Group4 Grpup5
Channel F S
B
×
4
C
×
4
F S
C
×
4
C
×
4
F S
D
0
×
4
D
1
×
4
F S
D
2
×
4
D
3
×
4
F S
A0
×
4
A1
×
4
I
Channel F S
B
×
4
C
×
4
F S
C
×
4
C
×
4
F S
D
0
×
4
D
1
×
4
F S
D
2
×
4
D
3
×
4
F S
A2
×
4
A3
×
4
I
Frame
Number0 1
2-
5
6-
910 11
12
-
15
16
-
19
20 21
22
-
25
26
-
29
30 31
32
-
35
36
-
39
40 41
42
-
45
46
-
49
501 multi-frame (51TDMA Frames) 235.38ms Uplink
Channel D3×4 R R A2×4 A3×4 R……R D0×4 D1×4 R R D2×4
Channel D0×4 R R A0×4 A1×4 R……R D0×4 D1×4 R R D2×4
Frame
Number0-3 4 5 6-9 10-13 14-36 37-40 41-44 45 46 47-50
F:FCCH; S:SCH; B:BCCH; C:CCCH; D:SDCCH ;A:SACCH; R:RACH; I:IDLE
Page37Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Structure of Logical Channel Combination Frame-Main SDCCH
1 multi-frame (51TDMA Frames) 235.38ms Downlink
ChannelD0
×4
D1
×4
D2
×4
D3
×4
D4
×4
D5
×4
D6
×4
D7
×4
A0
×4
A1
×4
A2
×4
A3
×4I I I
ChannelD0
×4
D1
×4
D2
×4
D3
×4
D4
×4
D5
×4
D6
×4
D7
×4
A4
×4
A5
×4
A6
×4
A7
×4I I I
Frame
Number0-3 4-7
8-
11
12-
15
16-
19
20-
23
24-
27
28-
31
32-
35
36-
39
40-
43
44-
47
4
8
4
9
5
0
1 multi-frame (51TDMA Frames) 235.38ms Uplink
ChannelA5
×4
A6
×4
A7
×4I I I
D0
×4
D1
×4
D2
×4
D3
×4
D4
×4
D5
×4
D6
×4
D7
×4
A0
×4
ChannelA1
×4
A2
×4
A3
×4I I I
D0
×4
D1
×4
D2
×4
D3
×4
D4
×4
D5
×4
D6
×4
D7
×4
A4
×4
Frame
Number0-3 4-7
8-
1112 13 14
15-
18
19
-
22
23-
26
27-
30
31-
34
35-
38
39-
42
43-
46
47-
50
D:SDCCH; A:SACCH; I:IDLE
Page38Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Structure of Logical Channel Combination Frame-TCH
T:TCH;A:SACCH; I:IDLE
1 multi-frame (26TDMA Frames) 120ms
Channel T T T T T T T…T A T,,,T T T T T T T I
Frame
Number0 1 2 3 4 5
6…
1112
13…
1819 20 21 22 23 24 25
1 multi-frame (26TDMA Frames) 120ms
Channel T t T t T t T…t A T,,,t T t T t T t a
Frame
Number0 1 2 3 4 5
6…
1112
13…
1819 20 21 22 23 24 25
Case of one full rate TCH
Case of two half rate TCHs
Page39Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
0 1 2 3 2044 2045 2046 2047
0 1 2 3 48 49 5047
0 1 24 25
0 1 24 25 1 49 500
0 1 4 5 762 3
TB3
TB3
GP8.25
TB: Tail bitTB3
TB3
GP8.25
GP: Guard periodTB3
TB3
GP8.25
TB3
TB3 GP 68.25
58 information bits26 training sequences 58 information bits
Constant bit 142
Information bit 39 Extended training sequence 64 Information bit 39
Synchronous sequence 41 Information bit 36
Normal burst (NB)
Frequency correction burst (FB)
Synchronous burst (SB)
Access burst (AB)
1 hyper frame=2048 super-frames=2715648TDMA frames (3 hours, 28 minutes, 53 seconds and 760 milliseconds)
1 super-frame=1326TDMA frames (6.12 seconds)
1 multiframe=26TDMA frames (120ms) 1 multiframe=51TDMA frames (3060/13ms)
1TDMA frame=8 timeslots (120/26=4.615ms)
1 timeslot=156.25 bit duration (15/26=0.577ms)(1 bit duration: 48/13=3.68us)
BCCHCCCHSDCCH
TCHSACCH/TFACCH
Frame
Page41Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
PCH RACHAGCH
Downlink CCCH Uplink CCCH
How to determine the total CCCH resources of the cell? How to
allocate AGCH and PCH reasonably?
Configuration of Common Control Channel
Page42Copyright © 2008 Huawei Technologies Co., Ltd. All rights reserved.
Summary
In this course, we have learned:
Processing of Voice Signal
Radio Channel in Um Interface
Key Technical in Um Interface