Performance of relay-enabled uplink in cellular networks - a flow level analysis

Abstract

Abstract-Uplink users in cellular networks, such as UMTS/ HSPA, located at the edge of the cell generally suffer from poor channel conditions. Deploying intermediate relay nodes is seen as a promising approach towards extending cell coverage and increasing data rates. This paper focuses on the role of packet scheduling in cellular networks with relay nodes. In particular, two uplink scheduling schemes deploying the relay functionality in different ways are compared in performance to a reference scenario where relaying is not used. We derive expressions which characterize for each of the two relay-enabled schedulers the service area of a relay station as a function of the relay location and transmit power. The results show that the service area is significantly influenced by the type of scheduling. Examining the impact on the effective data rates of mobile stations shows that there is a combination of the relay's position and transmit power which optimizes uplink service. Furthermore, based on calculations of flow throughput, we show that relaying improves flow level performance of all users, including those who do not use the relay.

Impact of relaying on inter-cell interference in mobile cellular networks

“…The faster service offered by the relay to remote MSs translates to lower average number of active flows from which all MSs, independently of location, benefit, see Equation (5). These results strongly support our claim that evaluation at flow level is crucial for understanding the complex effects of relaying.…”

“…Indeed in [5] the authors show that on EUL for UMTS the data rates realized at the cell edge significantly improve when a relay is used. More importantly, the study shows that the flow throughput of all users rises independently whether they use a relay or not.…”

“…Relaying is typically considered either to improve coverage, see [3], [4], or to increase system capacity, see [5], [6]. Indeed in [5] the authors show that on EUL for UMTS the data rates realized at the cell edge significantly improve when a relay is used.…”

Analysis Methodology for Flow-Level Evaluation of a Hybrid Mobile-Sensor Network

“…Special attention is paid to the impact of flow dynamics, i.e., the generation of flows at arbitrary moments and arbitrary locations, which leads to a changing number of service requests. In previous studies, see [3,4], it was shown that flow dynamics are crucial for the performance of data traffic. We expect this to hold even stronger when several traffic classes are considered.…”