On multi‐cell admission control in CDMA networks

Abstract

SUMMARYWe consider a multi-cell (MC) code division multiple access (CDMA) system that supports multiple service classes, including peak rate allocated and elastic ones. Peak rate allocated sessions-when admitted into the system-transmit at a constant bit rate, while elastic sessions can be slowed down at the expense of increasing their residency time. Admitted sessions cause an instantaneous bit rate-dependent interference in neighbour cells. In this rather general setting, we propose a method to calculate the class-wise blocking probabilities as the functions of the estimated so-called inter-cell coupling factors. In the paper this coupling factor is the ratio between the uplink path gains to different Node-B:s (that can be easily obtained in a CDMA system from pilot measurement reports), but our model could include other coupling measures as well. We find that when these coupling factors are underestimated, the system may get into false states (FSs) or false rate states (FRSs) that lead to violating the noise rise threshold. As traffic becomes increasingly elastic, the probability of FSs decreases, but the probability of FRSs increases. Based on numerical results, we make the point that as the traffic becomes more elastic, avoiding the underestimation of these coupling factors as well as exercising MC admission control plays an increasingly important role in guaranteeing proper service quality.

Congestion Relief in CDMA Cellular Networks Using Multihop Inter-Cell Relay

“…WCDMA-based networks are interference limited, which means that their capacities are affected by usage, and mobility of users. Various proposals have been made to overcome this limitation including enhanced functionalities for radio resource management overseeing admission [1] and power control [2].…”

Uplink Power Based Admission Control in Multi-Cell Wcdma Networks With Heterogeneous Traffic

“…This scheme tries to improve the performance of the system by estimating the power increase due to the new user in the serving cell and also in the neighboring cells. In [7,8] both analytical and simulation models are presented to evaluate the MC-AC algorithm with different traffic scenarios when elastic services (services that allowed to be degraded) are considered. Apart from their bit rate and QoS requirements, service classes are characterized by their slow down factor which is a measure of how elastic the sessions of that class are.…”