GPRS Qos说明.docx
《GPRS Qos说明.docx》由会员分享,可在线阅读,更多相关《GPRS Qos说明.docx(22页珍藏版)》请在冰豆网上搜索。
GPRSQos说明
QOS
1.R97/R98QoS
R97/R98QoS(3个字节),包括下列参数:
Precedenceclass:
优先级
Delayclass:
延迟等级
Reliabilityclass:
可靠性
Peakthroughputclass:
峰值吞吐量
Meanthroughputclass:
平均吞吐量
2.R99QoS
R99QoS(11个字节),保留了原来的3个字节,增加了8个字节,新增如下参数:
TrafficClass:
业务类型
Deliveryorder:
传输顺序
DeliveryoferroneousSDU:
是否传输错误SDU
MaximumSDUsize:
最大SDU尺寸
Maximumbitrateforuplink:
上行最大比特率
Maximumbitratefordownlink:
下行最大比特率
ResidualBER:
剩余SDU错误率
SDUErrorratio:
SDU错误率
Transferdelay:
传输时延
Transferhandlingpriority:
传输处理优先级
Guaranteedbitrateforunlink:
保证的上行最大比特率。
Guaranteedbitratefordownlink:
保证的下行最大比特率
3.R5/R6QoS
R5/R6QoS(14个字节),除了原来11个字节后,又增加了3个字节,新增如下参数:
SignallingIndication
SourceStatisticsDescriptor
Maximumbitratefordownlink(extended)
Guaranteedbitratefordownlink(extended)
4.QoS字段结构
QoSIE结构(informationelementcoded)
8
7
6
5
4
3
2
1
QualityofserviceIEI
octet1
LengthofqualityofserviceIE
Octet2
00
spare
Delay
class
Reliability
class
octet3
Peak
throughput
0
spare
Precedence
class
octet4
000
spare
Mean
throughput
octet5
TrafficClass
Deliveryorder
DeliveryoferroneousSDU
Octet6
MaximumSDUsize
Octet7
Maximumbitrateforuplink
Octet8
Maximumbitratefordownlink
Octet9
ResidualBER
SDUerrorratio
Octet10
Transferdelay
TrafficHandlingpriority
Octet11
Guaranteedbitrateforuplink
Octet12
Guaranteedbitratefordownlink
Octet13
000
spare
Signal-lingIndicat-ion
SourceStatisticsDescriptor
Octet14
Maximumbitratefordownlink(extended)
Octet15
Guaranteedbitratefordownlink(extended)
Octet16
Figure10.5.138/3GPPTS24.008:
Qualityofserviceinformationelement
5.Allocation/RetentionPriority
在Gb/Iu信令中,qos的字节长度如上,但在Gn的信令中,qos中会自动增加1个字节:
Allocation/Retentionpriority。
Allocation/RetentionPriority
Definition:
specifiestherelativeimportancecomparedtootherUMTSbearersforallocationandretentionoftheUMTSbearer.TheAllocation/RetentionPriorityattributeisasubscriptionattributewhichisnotnegotiatedfromthemobileterminal.
NOTE4:
Theadditionofauser-controlledAllocation/RetentionPriorityattributeisforfurtherstudyinfuturereleases.
[Purpose:
Priorityisusedfordifferentiatingbetweenbearerswhenperformingallocationandretentionofabearer.Insituationswhereresourcesarescarce,therelevantnetworkelementscanusetheAllocation/RetentionPrioritytoprioritizebearerswithahighAllocation/RetentionPriorityoverbearerswithalowAllocation/RetentionPrioritywhenperformingadmissioncontrol.]
6.QOS的取值
6.1PrecedenceClass
PrecedenceClass:
definestherelativeimportanceofmaintainingtheserviceunderabnormalconditions(e.g.,congestion).Threeprecedenceclassesaredefined:
Highpriority,Normalpriorityandlowpriority.Thepossibleprecedenceclassesaregiveninthefollowingtable:
Precedence
PrecedenceName
Interpretation
1(001)
Highpriority
Servicecommitmentsshallbemaintainedaheadofprecedenceclasses2and3.
2(010)
Normalpriority
Servicecommitmentsshallbemaintainedaheadofprecedenceclass3.
3(011)
Lowpriority
Servicecommitmentsshallbemaintainedafterprecedenceclasses1and2.
Table1.Precedenceclasses
6.2DelayClass
DelayClass:
definestheMStofixedstation(PDN)orfixedstationtoMStransferdelay.MorespecificallyitisthetotaldelaymeasuredbetweentheRorSandtheGireferencepoints(seefigure1).Fourdelayclassesareintroduced.Delayclasses1to3prescribeameantransferdelay(inseconds)andthe95percentiledelay(inseconds)betweentheabovereferencepoints(class1beingthemorestringentintermsofvalue).Delayclass4isa« besteffort »classwheretheGPRSnetworkgivesnoguaranteeregardingthedelayincurredbyuserpacketsassociatedwiththePDPcontext.Thepossibledelayclassesaregiveninthefollowingtable:
Delay(maximumvalues)
SDUsize:
128octets
SDUsize:
1024octets
DelayClass
MeanTransferDelay(sec)
95percentile
Delay(sec)
MeanTransfer
Delay(sec)
95percentile
Delay(sec)
1.(Predictive)001
<0.5
<1.5
<2
<7
2.(Predictive)010
<5
<25
<15
<75
3.(Predictive)011
<50
<250
<75
<375
4.(BestEffort)100
Unspecified
Table2.Delayclasses
6.3ReliabilityClass
ReliabilityClass:
fivereliabilityclassesdefinedecreasingreliabilityquality.Theyrangefromclass1wheredatapacketsshouldbedeliveredinsequencewithoutlosses,corruption,orduplication,toclass5wherealloftheaboveeventscanoccur.EachreliabilityclassisdeterminedbycombiningthetransmissionmodesofGTP,LLC,andRLCasshowninthefollowingtable:
ReliabilityClass
GTPMode
LLCFrameMode
LLCDataProtection
RLCBlockMode
TrafficType
1(001)
Acknowledged
Acknowledged
Protected
Acknowledged
Nonreal-timetraffic,error-sensitiveapplicationthatcannotcopewithdataloss.
2(010)
Unacknowledged
Acknowledged
Protected
Acknowledged
Nonreal-timetraffic,error-sensitiveapplicationthatcancopewithinfrequentdataloss.
3(011)
Unacknowledged
Unacknowledged
Protected
Acknowledged
Nonreal-timetraffic,error-sensitiveapplicationthatcancopewithdataloss,GMM/SM,andSMS.
4(100)
Unacknowledged
Unacknowledged
Protected
Unacknowledged
Real-timetraffic,error-sensitiveapplicationthatcancopewithdataloss.
5(101)
Unacknowledged
Unacknowledged
Unprotected
Unacknowledged
Real-timetraffic,errornon-sensitiveapplicationthatcancopewithdataloss.
Table3.Reliabilityclasses
6.4PeakThroughputClass
PeakThroughputClass:
measuredattheGiandRreferencepoints,itspecifiesthemaximumrateatwhichthedataisexpectedtobetransferredacrosstheGPRSnetworkforagivenPDPcontext.Notethatthenetworkisnotliabletoguaranteethatthispeakrateissustainableforanytimeperiod;thenetworkmaylimitthepeakthroughputtothenegotiatedrateevenifadditionaltransmissioncapacityisavailable.9peakthroughputclassesrangingfrom1(upto8Kbit/s)to9(upto2048Kbit/s)aredefinedasshowninthefollowingtable:
PeakThroughputClass
PeakThroughputinoctetspersecond
1
Upto1 000(8 kbit/s).
2
Upto2 000(16 kbit/s).
3
Upto4 000(32 kbit/s).
4
Upto8 000(64 kbit/s).
5
Upto16 000(128 kbit/s).
6
Upto32 000(256 kbit/s).
7
Upto64 000(512 kbit/s).
8
Upto128 000(1 024 kbit/s).
9
Upto256 000(2 048 kbit/s).
Table4.Peakthroughputclasses
6.5MeanThroughputClass
MeanThroughputClass:
measuredattheGiandRreferencepoints,itspecifiestheaveragerateatwhichthedataisexpectedtobetransferredacrosstheGPRSnetworkduringtheremaininglifetimeofagivenPDPcontext.Thenetworkmaylimitthemeanthroughputtothenegotiatedrateevenifadditionaltransmissioncapacityisavailable.Themeanthroughputclassesaredefinedinthefollowingtable:
MeanThroughputClass
MeanThroughputinoctetsperhour
1
100(~0.22 bit/s).
2
200(~0.44 bit/s).
3
500(~1.11 bit/s).
4
1 000(~2.2 bit/s).
5
2 000(~4.4 bit/s).
6
5 000(~11.1 bit/s).
7
10 000(~22 bit/s).
8
20 000(~44 bit/s).
9
50 000(~111 bit/s).
10
100 000(~0.22 kbit/s).
11
200 000(~0.44 kbit/s).
12
500 000(~1.11 kbit/s).
13
1 000 000(~2.2 kbit/s).
14
2 000 000(~4.4 kbit/s).
15
5 000 000(~11.1 kbit/s).
16
10 000 000(~22 kbit/s).
17
20 000 000(~44 kbit/s).
18
50 000 000(~111 kbit/s).
31
Besteffort.
Table5.Meanthroughputclasses
7.Qos的相关规范和文档
24.008Corenetworkprotocols
23.107QoSConceptandArchitecture
8.Qos的作用
在3G系统中,通过Qos保证机制的支持(也即服务质量的支持)可以实现业务的分级服务及用户的分类服务功能,即实现:
1)不同的业务可分配不同的资源以保证其所属业务级别的业务质量,同时使网络具有合理的资源利用率;
2)不同的用户可签约不同的服务级别,从而获得其所属类型的质量要求。
3G网络服务质量(QOS)的实现机制如下:
1)HLR中对每个用户所能够获得的业务类型应设置相应的QoS参数;
2)终端采用3GPP规定的标准QoS协商流程,发起业务时需携带QoS参数;
3)网络侧需要能够根据HLR中签约数据和业务的Qos需求来分配资源,保证业务质量。
用户分类服务的目的主要是满足不同级别用户,不同的业务质量的需求。
其基本机制包括数据业务用户的分类服务机制和话音业务用户的分类服务机制:
数据业务用户分类服务机制:
数据业务实现用户分类服务,主要功能要求如下:
1)能够给予不同类别用户在使用相同业务时,使用不同的业务速率;
2)在资源紧张时,用户能降速接入网络,高类别用户在接入时能够抢占低类别用户资源接入网络;
3)在资源紧张时,处于连接状态的用户能够降低正在使用的业务速率以保证网络稳定性。
在降速的顺序上,要优先考虑用户类别,再考虑业务的重要程度,最后考虑业务承载类型;
4)对于用户使用非实时业务,要求为高优先级用户的非实时业务设置较高的最低保障速率,在资源紧张时,做降速率处理时用户速率不低于最低保障速率。
话音业务用户分类服务机制:
对于3G话音业务,要求有给予不同类别的用户在业务建立阶段分配不同的话音编码速率的功能。
且能够根据网络资源紧张情况灵活打开/关闭该功能。
业务级别
特点
应用示例
会话级别
conversational
对时延和时延抖动要求严格、对丢包/误码率有较强容忍度
VoIP、分组域的可视电话
流级别
streaming
对时延抖动要求严格、对时延、丢包/误码率有较强容忍度
流媒体
交互级别
interactive
对时延性要求较高,对时延抖动没有要求,对丢包/误码率要求高
位置服务、WAP浏览
后台级别
background
对时延要求不高,对时延抖动没有要求,对丢包/误码率要求高
手机邮箱
9.HLR中qos的设置
HLR中要么给用户设置R97/98的qos,要么给用户设置R99的qos。
SGSN将根据规范进行qos的自动映射。
9.1R97/98qos和R99qos的互相转化
R97/R98=>R99:
Table6:
RulesfordeterminingR99attributesfromR97/98attributes
ResultingR99Attribute
DerivedfromR97/98Attribute
Name
Value
Value
Name
Trafficclass
Interactive
1,2,3
Delayclass
Background
4
Traffichandlingpriority
1
1
Delayclass
2
2
3
3
SDUerrorratio
10-6
1,2
Reliabilityclass
10-4
3
10-3
4,5
Residualbiterrorratio
10-5
1,2,3,4
Reliabilityclass
4*10-3
5
DeliveryoferroneousSDUs
'no'
1,2,3,4
Reliabilityclass
'yes'
5
Maximumbitrate[kbps]
8
1
Peakthroughputclass
16
2
32
3
64
4
128
5
256
6
512
7
1024
8
2048
9
Allocation/Retentionpriority
1
1
Precedenceclass
2
2
3
3
Deliveryorder
yes'
yes'
ReorderingRequired(InformationintheSGSNandtheGGSNPDPContexts)
'no'
'no'
MaximumSDUsize
1500octets
(Fixedvalue)
R99=>R97/R98:
Table7:
RulesfordeterminingR97/98attributesfromR99attributes
ResultingR97/98Attribute
DerivedfromR99Attribute
Name
Value
Value
Name
Delayclass
1
conversational
Trafficclass
1
streaming
Trafficclass
1
Interactive
Trafficclass
1