The Wireless Gateway Of Self-similar Data Streams

Due to the important consequences of traffic self-similarity in network design and network protocol, some studies have assumed that wireless traffic is also self-similar by follow reasons. First of all, it is true that recent advances in wireless networks such as IEEE802.11, Bluetooth, GPRS and WiMAX can enable high-speed communication and that high-speed wireless users tend to have the same bandwidth requirements as wired users when accessing the Internet. Second, one plausible justification of self-similarity in wireless traffic could be TCP effects. The loss rate here is higher than that of cable traffic, thus, TCP could generate self-similarity in the wireless traffic even more so as it does in the cable case. Last, the self-similarity of cable traffic may be propagated to wireless network when cable traffic is fed to the wireless network via a wireless gateway.However, due to factors such as power limitations and the wireless channel, the change of the self-similarity is the main research in this thesis as cable self-similar traffic is passed to the wireless network through a wireless gateway. In order to facilitate the mathematical analysis, this thesis simplifys the wireless gateway with data cache, re-package and forward, and it operates under "instant transfer" and "power control" mode. On the basis of the reference one, this thesis provides an analytical study of the propagation of traffic characteristics as cable traffic is passed to the wireless network through a gateway. The MATLAB software simulation results show that:1. When the gateway operates under "power control" mode with its buffer equaled to wireless channel capacity, the incoming traffic and the outgoing traffic of the wireless gateway will be ON/OFF stochastic process, and the tail index of the ON states durations of the outgoing traffic will be the same as in the incoming traffic, while the tail index of the OFF states durations will be the little one of two states durations of the incoming traffic. The self-similarity of outgoing traffic will be the same as incoming traffic.2. When the gateway operates under "power control" mode with large buffer, the tail index of the ON states durations of the outgoing traffic will increase by one, while the tail index of the OFF states durations will be the same as in the incoming traffic. The self-similarity of the outgoing traffic will increase.3. When the gateway operates under "instant transfer" mode, the tail index of states duration of outgoing traffic is the same as the incoming traffic, and the self-similarity of outgoing traffic will not change too.Another study of this thesis is the buffer content distribution of the wireless gateway. Theoretical analysis and MATLAB software simulation results show that: the buffer content of the wireless gateway will be Pareto distribution, and its parameters satisfy: a = min(a_A, a₁)-1.