On the Use of Multiple Hops in Next Generation Wireless Systems

Abstract

Traditional cellular networks provide a centralized wireless networking paradigm within the wireless domain with the help of fixed infrastructure nodes such as Base Stations (BSs). On the other hand, Ad hoc wireless networks provide a fully distributed wireless networking scheme with no dependency on fixed infrastructure nodes. Recent studies show that the use of multihop wireless relaying in the presence of infrastructure based nodes improves system capacity of wireless networks. In this paper, we consider three recent wireless network architectures that combine the multihop relaying with infrastructure support -namely Integrated Cellular and Ad hoc Relaying (iCAR) system, Hybrid Wireless Network (HWN) architecture, and Multihop Cellular Networks (MCNs), for a detailed qualitative and quantitative performance evaluation. MCNs use multihop relaying by the Mobile Stations (MSs) controlled by the BS. iCAR uses fixed Ad hoc Relay Stations (ARSs) placed at the boundaries to relay excess traffic from a hot cell to cooler neighbor cells. HWN dynamically switches its mode of operation between a centralized Cellular mode and a distributed Ad hoc mode based on the throughput achieved. An interesting observation derived from these studies is that, none of these architectures is superior to the rest, rather each one performs better in certain conditions. MCN is found to be performing better than the other two architectures in terms of throughput, under normal traffic conditions. At very high node densities, the variable power control employed in HWN architecture is found to be having a superior impact on the throughput. The mobility of relay stations significantly influences the call dropping probability and control overhead of the system and hence at high mobility iCAR which uses fixed ARSs is found to be performing better.

Performance evaluation of routing protocols for MANETs with known connectivity patterns using evolving graphs

“…This is important for benchmarking purposes, since the EG may be generated and used as a reference when developing or tuning routing protocols and mobility models. Furthermore, there are many practical situations, like those shown in [1,8,14,20,36], in which an EG can be built before the routing phase.…”

Resource Sharing via Planed Relay for

“…We summarise in Table 1 the main research improvements from the HWN * stage I [4] to the HWN * stage II. The comparison between the [4,8] with the identification of technologies used. Consider a cellular handover scenario in Figure 2 where MT A is currently connected to MT B and is moving out of Cell 1 into Cell 6.…”

On the Evaluation of Shortest Journeys in Dynamic Networks

“…When developing or tuning routing protocols or mobility models, the EG may be generated and used as a reference. On the other hand, there are many practical situations, like those shown in [1,6,15,26], in which an EG can be built before the routing phase.…”