Download - 01 Radio Resource Administration MO v3.1
© NOKIA BSSPAR / 11.2006-V3
Radio Resource Administration
CHAPTER 1
© NOKIA BSSPAR / 11.2006-V3
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© NOKIA BSSPAR / 11.2006-V3
Module Objectives• Give an overview about the TDMA frame structure
• Describe the logical channels, their mapping to TDMA frames and their parameters
• Demonstrate, how the signalling capacity effect the mapping of the logical channels
• Give an overview about the use of extended cells
• Describe the purpose of the Base Station Identity Code and the Training Sequence Code
• Explain the use of FDMA and frequency reuse
• Discuss the parameter settings required for base band and RF frequency hopping
© NOKIA BSSPAR / 11.2006-V3
Basic TDMA StructureRadio
Resource Administration
TDMA frame= 8 timeslots = 4.615 ms
01
34
5
76
01
23
45
76
01
23
45
200 kHz
physical channel e.g. allocated to onesubscriber with FR voiceand no frequency hopping
frequency
time
TDMA frame2
2 2 2
© NOKIA BSSPAR / 11.2006-V3
Multi, Super and Hyper FrameRadio
Resource Administration
0 1 2 49 500 1 2 24 25
0 2047
0 1 2 4849500 1 24 25
0 7
2048 super frames = hyper frame
Super frame = 26 x 51 multi frames or 51 x 26 multi frames
26 multi frame = 120 ms 51 multi frame = 235 ms
TDMA frame = 4.615 ms
TDMA frame numbering
0 1 2 49 50
© NOKIA BSSPAR / 11.2006-V3
GSM Channel OrganisationRadio
Resource Administration
Base StationSubsystem
Logical Channelsfor transport of specific content
Physical Channelstransport medium
MS
mapping
Physical channel parametersARFCNTime slot numberFrequency hopping algorithm
© NOKIA BSSPAR / 11.2006-V3
Logical ChannelsRadio
Resource Administration
SCH
FCCH
PCH
BCCH
AGCH
RACH
SDCCH
NCH
SACCH
...
FACCH
Stand alone Dedicated Control Channel
Frequency Correction Channel
Synchronisation Channel
Broadcast Control Channel
Paging Channel
Slow Associated Control Channel
Fast Associated Control Channel
Paging Channel
Random Access Channel
Access Grant Channel
Notification Channel
BCH
CCCH
DCCH
TCH
DL
DL
DL
DL
UL
CommonChannels
DedicatedChannels
UL/DL
UL/DL
CBCH Cell Broadcast Channel
© NOKIA BSSPAR / 11.2006-V3
Traffic ChannelsRadio
Resource Administration
TCH
TCH/EFR
TCH/FR TCH for Full Rate speech
TCH for Enhanced Full Rate speech
TCH/F9.6
TCH/HR TCH for Half rate Speech
TCH for full rate data transmission with 9.6 kbit/s
TCH/H4.8
TCH/F4.8 TCH for full rate data transmission with 4.8 kbit/sTCH for half rate data transmission with 4.8 kbit/s
TCH/H.2.4
TCH/F2.4 TCH for full rate data transmission with 2.4 kbit/sTCH for half rate data transmission with 2.4 kbit/s
...
© NOKIA BSSPAR / 11.2006-V3
Traffic Channel MappingRadio
Resource Administration
...
26 TDMA frames = 120 ms
1 26
t t tt t t t ft tt t t tt t t tt ft t t ttts i
Full Rate Traffic Channel Configuration (UL & DL)
Half Rate Traffic Channel Configuration (UL & DL)
26 TDMA frames = 120 ms
1 26
t
T T
t t
T
tf
t t
T T T T
t t
T
t
Tf
T
t
T
tt
T
s
S
t = full rate TCH, s = SACCH/T, i = idle TDMA frame
t = half rate TCH, s = SACCH/T (first user)T = half rate TCH, S = SACCH/T (second user) TDMA frame
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
AdministrationSignalling Channel Mapping
(BCCH + SDCCH/4 + SACCH/C4)
f s ff s f s
Downlink51 TDMA frames = 235 ms
-
Uplink
BCCH CCCH
f s f s
CCCH CCCHSDCCH 0
SDCCH 1SDCCH 2
SDCCH 3SACCH
0/2 SACCH1/3
r r f r r rr r r r fr r r r r rr r r r fr r r r rr f r r
1 51
SACCH2/0 SACCH
3/1
SDCCH 0SDCCH 1SDCCH 3
SDCCH 3
f = FCCH, s = SCH, r = RACH TDMA frame- = dummy burst
51 TDMA frames = 235 ms
1 51
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
AdministrationSignalling Channel Mapping
(BCCH +CCCH/9)
f s ff s f s
Downlink51 TDMA frames = 235 ms
-
Uplink
BCCH CCCH
f s f s
CCCH CCCH
r r f r r rr r r r fr r r r r rr r r r fr r r r rr f r r
1 51
CCCH CCCH CCCH CCCH CCCH CCCH
r rr r rr r r r r r r rr r r r r rr rr r r
f = FCCH, s = SCH, r = RACH TDMA frame- = dummy burst
51 TDMA frames = 235 ms
1 51
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
AdministrationSignalling Channel Mapping
(SDCCH/8 +SACCH/C4)
f
f
i = idle TDMA frame
f
51 TDMA frames = 235 ms
iii
iii
SDCCH 0SDCCH 1
SDCCH 2SDCCH 3
SDCCH 4SDCCH 5
SDCCH 6SDCCH 7
SDCCH 1SDCCH 2
SDCCH 3SDCCH 4
SDCCH 5SDCCH 6
SDCCH 7SDCCH 0
Downlink
Uplink
SACCH0/4 SACCH
1/5
SACCH2/6 SACCH
3/7
SACCH6/2 SACCH
7/3
SACCH4/0SACCH
5/1
51 TDMA frames = 235 ms
1 51
1 51
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
AdministrationChannel Mapping
(Parameter Setting)
Channel configuration defined by parameter channelType
TCHF = full rate traffic channelTCHH = half rate traffic channelTCHD = dual rate traffic channelERACH = random access channel of extended areaNOTUSED = timeslot has no radio definition or Abis allocationSDCCH = SDCCH/8 +SACCH/C4MBCCH = broadcast control channelMBCCHC = BCCH + SDCCH/4 + SACCH/C4MBCCB = BCCH + SDCCH/4 with CBCHSDCCB = SDCCH with CBCHMPBCCH = PBCCH + PCCCH + PTCCH packet control channels
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
Administration
Static SDCCHs overbooked-> Free TCHs used for SDCCH traffic
Rules for dynamic SDCCH allocation:
• SDCCH is configured to TRX with least number of SDCCHs or no SDCCHs yet at all• SDCCH is configured to TRX with least number of occupied channels• If between different types of TCHs must be selected, the preference order is: HR, FR, DR TCH• Intelligent underlay overlay network: dynamic SDCCHs supported by regular TRXs only
Dynamic SDCCH allocation + FACCH call set up enabled simultaneously-> dynamic SDCCH allocation has higher priority
Exceptions:
• Configuration of any dynamic SDCCH resource in the BTS not possible• Only one TCH of the BTS is available
Dynamic SDCCH Allocation
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
Administration
Alternative to dynamic SDCCH allocation
• Assignment of TCH to MS from CCCH instead of SDCCH• Call set up on FACCH instead on SDCCH
Parameters
newEstabCausesSupport Y/N Enables feature is generalordinaryCallOnFacch Y/N Enables ordinary call set up on FACCHemerCallOnFacch Y/N Enables emergency call set up on FACCHreestablishOnFacch Y/N Enables call reestablishment on FACCH
FACCH Call Set Up
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
Administration
Mobile terminating call -> MSC performs paging
MS identifies paging message with the IMSI/TMSIMS listens to own paging group only
BSC parameters
noOfMultiframesBetweenPaging 2..9 multi frames Defines how often MS listens to
paging
MSC parameters
Repaging Interval 50..100 ms Time between consecutive pagingattempts
Repaging Attempts 0..5 Number of paging repetitions
Buffering
BTS stores up to 8 paging messages of the MSC in page group bufferBTS sends paging messages to MS according noOfMultiframesBetweenPaging
PCH Parameters
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
Administration
Mobile sends channel requests to BTS seperated by random time intervals in case of no answer!
Parameters
maxNumberRetransmission 1,2,4,7 Defines maximum allowednumber of retransmissions
numberOfSlotsSpreadTrans 3..12,14,16,20,25,32,50 Defines time interval between
consecutive retransmissions
Random time interval between consecutive retransmissions
t = S + random [0,.. numberOfSlotsSpreadTrans – 1] RACH slots
S depends on numberOfSlotsSpreadTranssignalling channel mapping (CCCH + SDCCH combined or not in one multi
frame)
RACH Parameters
numberOfSlotsSpreadTrans = 10 signalling channel mapping = not combined -> S = 58 -> t = 58..67 time channel
requests
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
Administration
Network gives the MS dedicated resources
Downlink CCCH blocks
PCH can be used for AGCH messagesAGCH cannot be used for PCH messages
Reservation of CCCH blocks for AGCH
noOfBlocksForAccessGrant 0..7 possible number, if CCCH and SDCCH are not combined1..7 possible number, if CBCH is used in non combined
configuration0..2 possible number, if CCCH and SDCCH are combined
Preference of AGCH messages on PCH
noOfBlocksForAccessGrant 0 PCH can be used only, if no paging messages have to be send
= 0 AGCH messages have higher priority than PCH ones
Number of paging groups
N = (number of CCCH blocks – noOfBlocksForAccessGrant) * noOfMultiframesBetweenPaging
AGCH Parameters
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
Administration Erlang B Table
Chs 1% 2% 3% 5% Chs 1% 2% 3% 5%
1 0 .0 1 0 .0 2 0 .0 3 0 .0 5 21 1 2 .8 0 1 4 .0 0 1 4 .9 0 1 6 .2 0
2 0 .1 5 0 .2 2 0 .2 8 0 .3 8 22 1 3 .7 0 1 4 .9 0 1 5 .8 0 1 7 .1 0
3 0 .4 6 0 .6 0 0 .7 2 0 .9 0 23 1 4 .5 0 1 5 .8 0 1 6 .7 0 1 8 .1 0
4 0 .8 7 1 .0 9 1 .2 6 1 .5 2 24 1 5 .3 0 1 6 .6 0 1 7 .6 0 1 9 .0 0
5 1 .3 6 1 .6 6 1 .8 8 2 .2 2 25 1 6 .1 0 1 7 .5 0 1 8 .5 0 2 0 .0 0
6 1 .9 1 2 .2 8 2 .5 4 2 .9 6 26 1 7 .0 0 1 8 .4 0 1 9 .4 0 2 0 .9 0
7 2 .5 0 2 .9 4 3 .2 5 3 .7 5 27 1 7 .8 0 1 9 .3 0 2 0 .3 0 2 1 .9 0
8 3 .1 3 3 .6 3 3 .9 9 4 .5 4 28 1 8 .6 0 2 0 .2 0 2 1 .2 0 2 2 .9 0
9 3 .7 8 4 .3 4 4 .7 5 5 .3 7 29 1 9 .5 0 2 1 .0 0 2 2 .1 0 2 3 .8 0
10 4 .4 6 5 .0 8 5 .5 3 6 .2 2 30 2 0 .3 0 2 1 .9 0 2 3 .1 0 2 4 .8 0
11 5 .1 6 5 .8 4 6 .3 3 7 .0 8 31 2 1 .2 0 2 2 .8 0 2 4 .0 0 2 5 .8 0
12 5 .8 8 6 .6 1 7 .1 4 7 .9 5 32 2 2 .0 0 2 3 .7 0 2 4 .9 0 2 6 .7 0
13 6 .6 1 7 .4 0 7 .9 7 8 .8 3 33 2 2 .9 0 2 4 .6 0 2 5 .8 0 2 7 .7 0
14 7 .3 5 8 .2 0 8 .8 0 9 .7 3 34 2 3 .8 0 2 5 .5 0 2 6 .8 0 2 8 .7 0
15 8 .11 9 .0 1 9 .6 5 1 0 .6 0 35 2 4 .6 0 2 6 .4 0 2 7 .7 0 2 9 .7 0
16 8 .8 8 9 .8 3 1 0 .5 0 11 .5 0 36 2 5 .5 0 2 7 .3 0 2 8 .6 0 3 0 .7 0
17 9 .6 5 1 0 .7 0 11 .4 0 1 2 .5 0 37 2 6 .4 0 2 8 .3 0 2 9 .6 0 3 1 .6 0
18 1 0 .4 0 11 .5 0 1 2 .2 0 1 3 .4 0 38 2 7 .3 0 2 9 .2 0 3 0 .5 0 3 2 .6 0
19 11 .2 0 1 2 .3 0 1 3 .1 0 1 4 .3 0 39 2 8 .1 0 3 0 .1 0 3 1 .5 0 3 3 .6 0
20 1 2 .0 0 1 3 .2 0 1 4 .0 0 1 5 .2 0 40 2 9 .0 0 3 1 .0 0 3 2 .4 0 3 4 .6 0
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
Administration Paging Example
Combined CCCH / SDCCH configuration
noOfBlocksForAccessGrant = 1 -> 2 CCCH blocks for PCH
3 MSs paged per paging message -> 3 pages per block
2 blocks per multi frame -> 3 * 2 = 6 pages per multi frame
Number of pages per hour -> 3600 s / 0.235 s * 6 = 91915
2 pages required per MS -> 91915 / 2 = 45957 MSs per hour
BTS 3 MS
Paging_Request
BTS 3 MS
Paging_Request
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
Administration
Cell with 325 subscribers
1 call per subscriber once in a hour
1 location update (LU) per subscriber once in 2 hours
Duration of call assignment = 7 s -> 7 s / 3600 s = 1.94 mErl on SDCCH per subscriber
325 subscribers -> 325 * 1.94 mErl = 0.6305 Erl on SDCCH
Reservation time for LU = 7s -> 7 s / 7200 s = 0.97 mErl on SDCCH per subscriber
325 subscribers -> 0.3153 Erl on SDCCH
Total SDCCH traffic -> 0.6305 Erl + 0.3153 Erl = 0.9458 Erl
Blocking probability = 1% -> 5 SDCCHs required -> not combined with CCCH
Call Establishment &Location Update Example
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
Administration
Same cell with 325 subscribers
Additional SMS traffic of 1 mErl per subscriber
325 subscribers -> 325 * 1 mErl = 0.325 Erl on SDCCH
Total SDCCH traffic -> 0.6305 Erl + 0.3153 Erl + 0.325 Erl = 1.2708
Blocking probability = 1% -> 5 SDCCHs required -> not combined with CCCH
Example Including SMS
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
AdministrationExtended Cell
(Implementation)Normal region (frequency f1)N-TRX (Parameter eTrxInd = N)
Extended region (frequency f2 except timeslot 0)E-TRX (Parameter eTrxInd = E)
E-TRX
0 1 2 3 4 5 6 7
N-TRX
0 1 2 3 4 5 6 7
f1 f1 f1 f1 f1 f1 f1 f1
BCCH/SDCCH
NotUsed
TCH TCH TCH TCH TCH TCH
TCH TCH TCH TCH TCH TCHRACHSDCCH
f1 f2 f2 f2 f2 f2 f2 f2
Extended cell sizeParameter radiusExtensionValue = 1..67 radius of extended cellValue = 0 ordinary cell
© NOKIA BSSPAR / 11.2006-V3
Radio Resource
AdministrationExtended Cell
(Cell Selection, Handover)
Cell Selection
MS can camp on normal or extended cell, independently on the distance to the BTS
Failure of RACH burst -> Wrong cell selectedReselection on the basis of the path loss criterion C1
Handover to due Distance
maxMSDistanceHOThreshold 0..63 63 = maximum allowed distancethreshold exceeded -> handover triggered
toextended cell
minMSDistanceHOThreshold 0..63 63 = maximum allowed distancethreshold exceeded -> handover triggered
tonormal cell
Handover due to other Reason
hoTargetArea 0..3 indicates type of target cell (normal or extended)
indicates type of transceiver from which the BSC tries to allocate a channel (normal or extended)
© NOKIA BSSPAR / 11.2006-V3
Base Station Identity CodeRadio
Resource Administration
Base Station Identity Code BSIC = Network Colour Code NCC + Base Station Colour Code BCC
bsIdentityCode Setting of BSIC
NCC 0..7, distinguishes between PLMNsBCC 0..7, distinguishes between clusters
BSIC + frequency channel -> unique identity of adjacent cell
f1f2f3
f1
f1
bcc = 1bcc = 2
bcc = 3
© NOKIA BSSPAR / 11.2006-V3
Training Sequence CodeRadio
Resource Administration
Training Sequence Code TSC
tsc 0..7 Setting of TSC
Used to determine signal distortion and bit error rate
trainingsequence
encrypted bitsencrypted bits3 31
stealing flag stealing flag
57 bits 57 bits26 bits
1
tail bits tail bits
Burst on TCH
data± difference =difference
expected bursttraining sequence ??
received burst
correlation
data* data*training sequence*
data*
© NOKIA BSSPAR / 11.2006-V3
200 kHz
890 915 935 960
1 2 3 4 124123 1 2 3 4 124123
duplex distance
Absolute radio frequency carrier number ARFCN
uplink direction downlink direction
Example: GSM 900
Frequency Division Multiple AccessRadio
Resource Administration
© NOKIA BSSPAR / 11.2006-V3
Frequency ReuseRadio
Resource Administration
Frequency to be used by TRX
initialFrequency Setting of ARFCNs
f1f2
f3f4
f5f6
f7
f1f2
f3f4
f5f6
f7
f1f2
f3f4
f5f6
f7
© NOKIA BSSPAR / 11.2006-V3
Frequency Information for MSRadio
Resource Administration
Idle mode -> MS listens on BCCH
idleStateBCCHAllocation 0..255 0 = MS gets frequency information frominitialFrequency lists of adjacent cells1..255 = MS gets frequency information fromdouble BCCH allocation list
bCCHAllocationList Indicates ARFCN values given by double BCCHallocation list
Dedicated mode -> MS listens on SACCH
measurementBCCHAllocation ADJ,IDLE ADJ = MS gets frequency information frominitialFrequency lists of adjacent cellsIDLE = MS uses same double BCCH allocation list as in idle mode
© NOKIA BSSPAR / 11.2006-V3
Frequency
Time
F1
F2
F3
Call is transmitted through several frequencies to• average the interference (interference diversity)• minimise the impact of fading (frequency diversity)
Principle of Frequency HoppingRadio
Resource Administration
Frequency hopping techniques
btsIsHopping BB,RF,NBB = base band hoppingRF = RF hoppingN = no frequency hopping at all
© NOKIA BSSPAR / 11.2006-V3
Baseband Hopping
TRX 1
TRX 2
TRX 3
0 1 72 Timeslot
TRX 4
BCCH
f 1
f 2
f 3
f 4
HSN1Timeslot 0 hops over TRXs 2-4 onlyBCCH does not hop
HSN2Timeslots 1-7 hop over all TRXs
Base Band HoppingRadio
Resource Administration
TRXs do not hopPhysical channels moved from one TRX to another
Hopping sequencehoppingSequenceNumber 0..63
0 = cyclic hopping1..63 = pseudorandom hopping
© NOKIA BSSPAR / 11.2006-V3
TRX 1
TRX 2
TRX 3
0 1 72 Timeslot
TRX 4
BCCH f1 – no hopping
f2,f3..fn – hopping accordingmobile allocation list One hopping sequencenumber only
RF Hopping(Standard Technique)
Radio Resource
Administration
TRXs do hop except TRX1 (provides BCCH)Up to 63 frequencies available defined by mobile allocation list -> better hopping gain
mobileAllocationList Setting of ARFCN values usedMobileAllocation 0..255 0 = BTS detached from any list
1..255 = indicates list which shall be used
© NOKIA BSSPAR / 11.2006-V3
MAI
-
0
1
2
-
3
4
5
-
6
7
8
MAIO
0
3
6
TRX-1 BCCH
TRX-2 TCH
TRX-3 TCH
TRX-4 TCH
TRX-5 BCCH
TRX-6 TCH
TRX-7 TCH
TRX-8 TCH
TRX-9 BCCH
TRX-10 TCH
TRX-11 TCH
TRX-12 TCH
RF Hopping(Freeform Hopping)
Sector 1
Sector 2
Sector 3
Standard technique
9 hopping hopping frequencies MAI = 0..8But 3 frequencies available for every TRX only
Freeform hopping
For every sector samemobile allocation listhopping sequence numberframe number (frame synchronization)
For every sector differentstarting points for hopping sequencepossible by mobile allocation index offset
maioOffset 0..62setting of MAIO
9 hopping hopping frequencies MAI = 0..89 frequencies available for every TRX
Radio Resource
Administration
© NOKIA BSSPAR / 11.2006-V3
MAIO
0
2
4
6
8
10
12
14
16
TRX-1 BCCH
TRX-2 TCH
TRX-3 TCH
TRX-4 TCH
TRX-5 BCCH
TRX-6 TCH
TRX-7 TCH
TRX-8 TCH
TRX-9 BCCH
TRX-10 TCH
TRX-11 TCH
TRX-12 TCH
RF Hopping(Flexible MAIO Management)
Sector 1
Sector 2
Sector 3
Freeform hopping
Not adequate for MA list with consecutive ARFCN valuesAvoids co-channel interferenceBut not adjacent channel interference
Flexible MAIO management
MAIO increases with constant step size from one TRX to the next one
maioStep 0..62
maioOffset = 0, 6, 12 for sector 1, 2, 3maioStep = 218 frequencies required (2 * number of hopping TRXs)
Radio Resource
Administration
© NOKIA BSSPAR / 11.2006-V3
BCCH
Band allocation:
MA listConsecutive ARFCN
Only BCCH frequency planning requiredOnly BCCH frequency planning required
Flexible MAIO managementMAIO Offset + MAIO Step
BCCH
Band allocation:
MA listDiscrete ARFCN
Freeform hoppingMAIO Offset
MA list and BCCH frequency planning requiredMA list and BCCH frequency planning required
RF Hopping(Tight Frequency Reuse)
Radio Resource
Administration
© NOKIA BSSPAR / 11.2006-V3
Frequency Plan ChangingRadio
Resource Administration
BSIC / TSCFrequenciesFrequency hopping settingIntelligent underlay overlay TRX settings