IST-2000-30148 I-METRA: D6.2 Implications in re-configurable systems beyond 3G (Part 2)

This activity evaluates the extension of the bandwidth of the UTRA MIMO HSDPA concept to 20 MHz, which is precisely the bandwidth of HIPERLAN/2. This would allow a fair comparison between the performance of UTRA MIMO HSDPA and the enhanced HIPERLAN/2. The bandwidth expansion would be the consequence of multiplying the chip rate of the W-CDMA spreading by four, i.e., 3.84 x 4 = 15.36 Mcps. A higher bandwidth MIMO channel model is necessary and this will be developed based on the channel model already developed in WP2. High data rates are required to satisfy the ever-increasing application requirements in future wireless communication systems. Recent investigations have indicated that a peak data rate of up to 20Mbps per user in the DL may be required for satisfactory reception of bursty traffic. As the transmission powers (of both mobile terminals and base stations) are limited, higher data rates lead to the reduction of the effective coverage area of a cell. That is, only users that are close to the base station will be able to communicate with high data rates, while users far away from the base station will only be able to use low data rates.Preprin

Multilevel Downlink Relay Queue Aware And Loss Recovery Scheduling For Media Transmission In Wireless Cellular Networks

In this document, we study the result of multi hop relaying on the throughput of the downstream channel in cellular networks. In particular, we contrast the throughput of the multi hop method through that of the conventional cellular system, representing the feasible throughput development by the multi hop relaying under transitive transmission considerations. We moreover propose a hybrid control plan for the multi hop communicate, in which we activist the use of in cooperation, the straight transmission and the transitive multi hop relaying. Our study illustrates that the majority of the throughput gain can be obtained with the related of a transitive relaying scheme. Important throughput improvement could be moreover obtained by operating the simultaneous relaying transmission in conjunction with the non simultaneous transmission. We also disagree here that the multi hop relaying technology can be developed for mitigating injustice in qualityof- service (QoS), which arrive due to the location-dependent signal quality. Our outcomes demonstrate that the multi hop system can provide more even QoS over the cell district. The multi hop cellular system design can also be used as a selfconfiguring network mechanism that efficiently contains variability of traffic distribution. We have studied the throughput development for the consistent, as well as for the non uniform traffic distribution, and we conclude that the utilization of transitive relaying in cellular networks would be relatively robust to alter in the actual traffic distribution

Resource Allocation in Ad Hoc Networks

Unlike the centralized network, the ad hoc network does not have any central administrations and energy is constrained, e.g. battery, so the resource allocation plays a very important role in efficiently managing the limited energy in ad hoc networks. This thesis focuses on the resource allocation in ad hoc networks and aims to develop novel techniques that will improve the network performance from different network layers, such as the physical layer, Medium Access Control (MAC) layer and network layer. This thesis examines the energy utilization in High Speed Downlink Packet Access (HSDPA) systems at the physical layer. Two resource allocation techniques, known as channel adaptive HSDPA and two-group HSDPA, are developed to improve the performance of an ad hoc radio system through reducing the residual energy, which in turn, should improve the data rate in HSDPA systems. The channel adaptive HSDPA removes the constraint on the number of channels used for transmissions. The two-group allocation minimizes the residual energy in HSDPA systems and therefore enhances the physical data rates in transmissions due to adaptive modulations. These proposed approaches provide better data rate than rates achieved with the current HSDPA type of algorithm. By considering both physical transmission power and data rates for defining the cost function of the routing scheme, an energy-aware routing scheme is proposed in order to find the routing path with the least energy consumption. By focusing on the routing paths with low energy consumption, computational complexity is significantly reduced. The data rate enhancement achieved by two-group resource allocation further reduces the required amount of energy per bit for each path. With a novel load balancing technique, the information bits can be allocated to each path in such that a way the overall amount of energy consumed is minimized. After loading bits to multiple routing paths, an end-to-end delay minimization solution along a routing path is developed through studying MAC distributed coordination function (DCF) service time. Furthermore, the overhead effect and the related throughput reduction are studied. In order to enhance the network throughput at the MAC layer, two MAC DCF-based adaptive payload allocation approaches are developed through introducing Lagrange optimization and studying equal data transmission period

Hop-limited routing for multihop cellular networks

In recent years, conventional cellular systems have experienced evolution in fields of data oriented services. During this period, the requirement for high data-rate stimulated new research proposals, which resulted in a new architecture: Multihop Cellular Networks (MCN), where multihop structure enables mobile stations to forward packets from other mobile stations to the base station on the uplink, and in turn, forward packets to other mobile stations from the base station on the downlink. In this thesis, a new routing algorithm is introduced for MCNs in order to limit the number of hops between the base station and the mobile stations with given delay constraints. The capacity of MCNs is restricted due to intensive traffic in the network since all nodes has the capability of sending packets simultaneously. The analysis of average end-to-end delay in high bitrate data transmission reveals that minimizing end-to-end delay with a proper scheduling scheme guarantees the aim of limiting number of hops in MCNs. The proposed algorithm showed that the intensive traffic can be absorbed by the base station by limiting the number of hops between the base station and the mobile stations