Deterministic Online Call Control in Cellular Networks and Triangle-Free Cellular Networks

TL;DR

This paper presents improved online algorithms for call control in cellular networks, achieving better competitive ratios and analyzing triangle-free network variants to optimize frequency utilization.

Contribution

It introduces a new 7/3-competitive algorithm for call control and a 9/4-competitive algorithm for triangle-free cellular networks, with proven lower bounds.

Findings

Achieved a 7/3 competitive ratio for cellular network call control.

Developed a 9/4 competitive algorithm for triangle-free networks.

Proved a lower bound of 5/3 for the competitive ratio in triangle-free networks.

Abstract

Wireless Communication Networks based on Frequency Division Multiplexing (FDM in short) plays an important role in the field of communications, in which each request can be satisfied by assigning a frequency. To avoid interference, each assigned frequency must be different to the neighboring assigned frequencies. Since frequency is a scarce resource, the main problem in wireless networks is how to fully utilize the given bandwidth of frequencies. In this paper, we consider the online call control problem. Given a fixed bandwidth of frequencies and a sequence of communication requests arrive over time, each request must be either satisfied immediately after its arrival by assigning an available frequency, or rejected. The objective of call control problem is to maximize the number of accepted requests. We study the asymptotic performance of this problem, i.e., the number of requests in the sequence and the bandwidth of frequencies are very large. In this paper, we give a 7/3-competitive algorithm for call control problem in cellular network, improving the previous 2.5-competitive result. Moreover, we investigate the triangle-free cellular network, propose a 9/4-competitive algorithm and prove that the lower bound of competitive ratio is at least 5/3.