In this thesis, we propose a system architecture that has multiple localized networks, each with a mobile information server (Mobile Infostation) that collects the information relevant to mobile users over a back-haul network and delivers theMoreIn this thesis, we propose a system architecture that has multiple localized networks, each with a mobile information server (Mobile Infostation) that collects the information relevant to mobile users over a back-haul network and delivers the information to the users on demand.
For efficient use of the bandwidth and energy resources of the wireless network, we design and evaluate a cross-layer solution for the Radio Link Control (RLC), Medium Access Control (MAC), and Transport layers of the network protocol stack.-At the RLC layer, we propose a Hybrid--ARQ scheme with transmit power control to optimize the average energy consumption while maintaining a target packet error rate (PER) to increase the reliability of the Link Layer.
We show that the above optimization problems for a short term static Rayleigh block fading MIMO channel can be formulated and solved using geometric programming. Our illustrative results show that, with a target PER of 0.01%, the optimal power allocation scheme can provide a gain of up to 3 dB for a Space-Time Trellis Code (STTC) coded MIMO channel with maximum two ARQ rounds.-At the MAC layer, we propose an efficient MAC scheme with two variations, where the data frames are scheduled for transmission based on the user priorities, channel conditions and mobility. In the reliable version of the MAC protocol named MIN-MACa, a stop-and-wait ARQ for data frames and a selective repeat ARQ for data sub-frames are combined to ensure reliable and efficient data transmission without the use of the TCP protocol.
A highly efficient version of the MAC protocol without the ARQ overhead named MIN-MACb is also proposed, thereby requiring an integrated transport protocol for reliable end-to-end data transmission.-At the Transport layer, a transport protocol (MIN-TCP) optimized for the MIN-MACb is proposed to improve the end-to-end throughput.
The simulation results show that, with MIN-TCP, the throughput can be doubled compared with TCP-NewReno when the PER is high. The cross-layer approach to the Transport and MAC layer co-design also provides higher throughput than the MIN-MACa approach when the PER is low.