QOS
1. R97/R98 QoS
R97/R98 QoS（3个字节），包括下列参数：
Precedence class:优先级 Delay class：延迟等级 Reliability class：可靠性
Peak throughput class：峰值吞吐量 Mean throughput class：平均吞吐量
2. R99 QoS
R99 QoS(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：
Traffic Class:业务类型 Delivery order:传输顺序
Delivery of erroneous SDU:是否传输错误SDU Maximum SDU size: 最大SDU 尺寸 Maximum bit rate for uplink :上行最大比特率 Maximum bit rate for downlink :下行最大比特率 Residual BER:剩余SDU 错误率 SDU Error ratio:SDU 错误率 Transfer delay: 传输时延
Transfer handling priority:传输处理优先级
Guaranteed bit rate for unlink:保证的上行最大比特率。 Guaranteed bit rate for downlink:保证的下行最大比特率
3. R5/R6 QoS
R5/R6 QoS(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：
Signalling Indication
Source Statistics Descriptor
Maximum bit rate for downlink (extended) Guaranteed bit rate for downlink (extended)
4. QoS字段结构
QoS IE 结构（information elementcoded）
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octet 1 Octet 2 Reliability class 0 spare Mean throughput Delivery order Delivery of erroneous SDU Octet 6 Maximum SDU size Maximum bit rate for uplink Maximum bit rate for downlink Residual BER Transfer delay Guaranteed bit rate for uplink Guaranteed bit rate for downlink 0 0 spare 0 Signal-ling Indicat-ion Maximum bit rate for downlink (extended) Guaranteed bit rate for downlink (extended) Octet 15 Octet 16 Octet 13 SDU error ratio priority Octet 12 Octet 7 Octet 8 Octet 9 Octet 10 Precedence class octet 5 octet 4 octet 3 Quality of service IEI Length of quality of service IE 0 0 Peak throughput 0 0 spare Traffic Class 0 Delay class spare Traffic Handling Octet 11 Source Statistics Descriptor Octet 14
Figure 10.5.138/3GPP TS 24.008: Quality of service information element
5. Allocation/Retention Priority
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/Retention priority。
Allocation/Retention Priority
Definition: specifies the relative importance compared to other UMTS bearers for allocation and retention of the UMTS bearer. The Allocation/Retention Priority attribute is a subscription attribute which is not negotiated from the mobile terminal.
NOTE 4: The addition of a user-controlled Allocation/Retention Priority attribute is for further
study in future releases.
[Purpose: Priority is used for differentiating between bearers when performing allocation and retention of a bearer. In situations where resources are scarce, the relevant network elements can use the Allocation/Retention Priority to prioritize bearers with a high Allocation/Retention Priority over bearers with a low Allocation/Retention Priority when performing admission
control.]
6. QOS的取值
6.1 Precedence Class
Precedence Class: defines the relative importance of maintaining the service under abnormal conditions (e.g., congestion). Three precedence classes are defined: High priority, Normal priority and low priority. The possible precedence classes are given in the following table:
Precedence Precedence Name High priority Interpretation Service commitments shall be maintained ahead of precedence classes 2 and 3. Service commitments shall be maintained ahead of precedence class 3. Service commitments shall be maintained after precedence classes 1 and 2. 1(001) 2(010) Normal priority 3(011) Low priority Table 1. Precedence classes
6.2 Delay Class
Delay Class: defines the MS to fixed station (PDN) or fixed station to MS transfer delay. More specifically it is the total delay measured between the R or S and the Gi reference points (see figure 1). Four delay classes are introduced. Delay classes 1 to 3 prescribe a mean transfer delay (in seconds) and the 95 percentile delay (in seconds) between the above reference points (class 1 being the more stringent in terms of value). Delay class 4 is a ? best effort ? class where the GPRS network gives no guarantee regarding the delay incurred by user packets associated with the PDP context. The possible delay classes are given in the following table: Delay Class Delay (maximum values) SDU size: 128 octets Mean Transfer Delay (sec) 1. (Predictive)001 2. (Predictive)010 3. (Predictive)011 4. (Best Effort)100 < 0.5 < 5 < 50 < 1.5 < 25 < 250 Delay (sec) SDU size: 1024 octets 95 percentile Delay (sec) Transfer Delay (sec) < 2 < 15 < 75 < 7 < 75 < 375 95 percentile Mean Unspecified Table 2. Delay classes
6.3 Reliability Class
Reliability Class: five reliability classes define decreasing reliability quality. They range from class 1 where data packets should be delivered in sequence without losses, corruption, or duplication, to class 5 where all of the above events can occur. Each reliability class is determined by combining the transmission modes of GTP, LLC, and RLC as shown in the following table: Reliability Class 1(001) Acknowledged GTP Mode LLC Frame Mode Acknowledged LLC Data Protection Protected RLC Block Mode Acknowledged Traffic Type Non real-time traffic, error-sensitive application that cannot cope with data loss. Non real-time traffic, error-sensitive application that can cope with infrequent data loss. Non real-time traffic, error-sensitive application that can cope with data loss, GMM/SM, and SMS. Real-time traffic, error-sensitive application that can cope with data loss. Real-time traffic, error non-sensitive application that can cope with data loss. 2(010) Unacknowledged Acknowledged Protected Acknowledged 3(011) Unacknowledged Unacknowledged Protected Acknowledged 4(100) Unacknowledged Unacknowledged Protected Unacknowledged 5(101) Unacknowledged Unacknowledged Unprotected Unacknowledged Table 3. Reliability classes
6.4 Peak Throughput Class
Peak Throughput Class: measured at the Gi and R reference points, it specifies the maximum rate at which the data is expected to be transferred across the GPRS network for a given PDP context. Note that the network is not liable to guarantee that this peak rate is sustainable for any time period; the network may limit the peak throughput to the negotiated rate even if additional transmission capacity is available. 9 peak throughput classes ranging from 1 (up to 8 Kbit/s) to 9 (up to 2048 Kbit/s) are defined as shown in the following table:
Peak Throughput Class 1 2 3 4 5 6 7 8 9 Peak Throughput in octets per second Up to 1 000 (8 kbit/s). Up to 2 000 (16 kbit/s). Up to 4 000 (32 kbit/s). Up to 8 000 (64 kbit/s). Up to 16 000 (128 kbit/s). Up to 32 000 (256 kbit/s). Up to 64 000 (512 kbit/s). Up to 128 000 (1 024 kbit/s). Up to 256 000 (2 048 kbit/s). Table 4. Peak throughput classes
6.5 Mean Throughput Class
Mean Throughput Class: measured at the Gi and R reference points, it specifies the average rate at which the data is expected to be transferred across the GPRS network during the remaining lifetime of a given PDP context. The network may limit the mean throughput to the negotiated rate even if additional transmission capacity is available. The mean throughput classes are defined in the following table: Mean Throughput Class 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 31 Mean Throughput in octets per hour 100 (~0.22 bit/s). 200 (~0.44 bit/s). 500 (~1.11 bit/s). 1 000 (~2.2 bit/s). 2 000 (~4.4 bit/s). 5 000 (~11.1 bit/s). 10 000 (~22 bit/s). 20 000 (~44 bit/s). 50 000 (~111 bit/s). 100 000 (~0.22 kbit/s). 200 000 (~0.44 kbit/s). 500 000 (~1.11 kbit/s). 1 000 000 (~2.2 kbit/s). 2 000 000 (~4.4 kbit/s). 5 000 000 (~11.1 kbit/s). 10 000 000 (~22 kbit/s). 20 000 000 (~44 kbit/s). 50 000 000 (~111 kbit/s). Best effort. Table 5. Mean throughput classes