Đang chuẩn bị liên kết để tải về tài liệu:
WIMAX, New Developments 2011 Part 15

Tham khảo tài liệu 'wimax, new developments 2011 part 15', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | WiMAX Cross-Layer System for Next Generation Heterogeneous Environments 371 Fig. 10. QoS reservation modification and deletion measurements Each stack column is further split in three parts each one corresponding to a specific action namely QoS session establishment blue modification purple and deletion white . For each action the vertical axis represents the cumulative average time in milliseconds - ms to enforce a specific action on the WiMAX system. As an example the blue part of the CSC column represents the cumulative average time composed by the CSC RC GA RSA and WiMAX BS modules to establish the SF reservations in the WiMAX system. The blue part of the RC column describes the QoS reservation cumulative average time composed by the RC GA RSA and WiMAX BS whereas the blue section of the GA column provides the cumulative average time given by the GA RSA and WiMAX BS modules. Finally the RSA column represents the internal module processing time as well as the SNMP management messages exchange with the WiMAX BS. On the horizontal axis is represented the number of SFs 2 8 32 64 128 256 that have been used for each test. Therefore each group of four columns represents a specific performance test. Comparing the obtained results with respect to the type of actions that are being requested to the WiMAX system we show that the required time to establish a QoS reservation blue is approximately 53 of the total time consumed. The rationale for this behavior is due to the fact that the amount of operations required by the WiMAX system for a QoS reservation is higher when compared to the modification and deletion processes. Figure 10 also shows that the most time consuming module is the RSA mainly because it includes the negotiation of the QoS parameters between the BS and the SS through the usage of the DSA C D Dynamic Service Addition Change Deletion messages as defined in the IEEE 802.16 standard which is the major time consuming process in the chain. The average time .