Performance Analysis of Uplink Packet Schedulers in Cellular Networks with Relaying

Abstract

Abstract. Deployment of intermediate relay nodes in cellular networks, e.g. UMTS/ HSPA, has been proposed for service enhancement, which is of particular importance for uplink users at the cell edge suffering from low power capacity and relatively poor channel conditions. In this paper, we propose and investigate a number of uplink packet scheduling schemes deploying the relay functionality in different ways. Using a combined packet and flow level analysis capturing the specifics of the scheduling schemes and the random behavior of the users (initiation and completion of flow transfers), the performance of the various schemes is evaluated and compared to a reference scenario where relaying is not used. The main performance measures considered in our study are the instantaneous data rate, the energy consumption and the mean flow transfer time. Interestingly, considering flow transfer times, it is found that the use of relay nodes is not only particularly beneficial for users at the cell edge but also has a strongly positive effect on the performance of users at locations close to the base station.

Uplink packet scheduling in cellular networks with relaying—comparative study

“…The graphs of SOBO and ExOBO coincide, since both schemes have the same received powers at BS and use only half the transmission time τ to transfer unique data, see (4). Furthermore, complying with our expectations, the two schemes are outperformed by SoptOBO.…”

“…Hence, for R(n) we can write: for MSs using relay path, (6) where n relay is the number of MSs which make use of the relay station. Note that r eff is different for each path according to (4).…”

“…In [4] we presented a comparative analysis of several packet schedulers which incorporated relaying. In particular, all schemes use the radio interface for the communication between a mobile and relay station and between a relay and base station.…”

“…In particular, all schemes use the radio interface for the communication between a mobile and relay station and between a relay and base station. The most prominent contributions of [4] were: incorporating the impact of flow level dynamics in terms of randomly changing number of active users and discussing variety of schedulers with relaying as opposed to the few options presented by other authors. The current study is an extension of [4] as we introduce several additional scheduling schemes, see Sect.…”

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

“…On the contrary, [16] proposes several deployment scenarios with detailed discussion on the spectrum utilization but does not consider the impact of particular scheduling schemes and other system characteristics. The effect a relay has on flow level performance on an uplink we discuss in [4]. However, the considered scenario of unlimited number of relay stations is somehow unpractical.…”