Dynamic allocation of downlink and uplink resource for broadband services in fixed wireless networks

Abstract

We propose and analyze a resource allocation algorithm, referred to as the Enhanced Staggered Resource Allocation (ESRA) method, for downlink and uplink in fixed broadband wireless networks with directional antennas at base stations and terminals. The new method is based on the Staggered Resource Allocation (SRA) algorithm proposed in [FHLQS98] with consideration of reception quality at terminal locations [QC97]. Terminals are categorized into multiple classes, depending on their ability to tolerate concurrent packet transmissions. The bandwidth is divided into mini-frames allowing different degrees of concurrent transmissions, thus packets of different classes are sent in the corresponding mini-frames. The purpose of the ESRA method is to maximize concurrent transmissions up to an extent tolerable by the receiving terminals for throughput improvement, while avoiding major co-channel interference in the networks where the same frequency band is re-used in every sector of every cell.For reasonable radio environment, practical antenna patterns and choices of system parameters, our performance analysis shows that the ESRA method provides 98.69% coverage, and yields a maximum downlink throughput of 36.10% per sector with success probability of one for packet transmission in terms of meeting a 15dB threshold for signal-to-interference ratio (SIR). As for the uplink, using full power control, the throughput can reach 16.7% per sector with a packet loss probability of less than 5 x 10 − 4 . The ESRA performance is compared favorably to existing methods such as the CPDA scheme[BFZA96] and the SRA method [FHLQS98]. The high ESRA throughput translates into a very large network capacity. In addition to data services, the high quality of service reveals the applicability of the new method to support real-time traffic such as voice and video. Therefore, we believe that the new approach represents an important step forward in providing broadband, multi-media services in fixed wireless networks.-2 -

Performance improvement of fixed wireless access networks by conjunction of dual polarization and time domain radio resource allocation technique

“…Time domain scheduling with S terminals per sector and full frequency reuse in the 2-11 GHz frequency bands are assumed. The service area is divided into hexagonal cells and triangular sectors [2,3]. Each sector is equipped with its own directional antenna and is labelled from 1 to 6 counter-clockwise, in such a way that there are no adjacent sectors bearing the same label ( Figure 1).…”

“…Each subframe is further divided into six mini-frames allowing different degrees of concurrent transmissions in each subframe [2,3]. The degree of concurrent transmissions of each mini-frame is denoted by its label (Figure 2).…”

“…Each terminal is classified, for a given SINR threshold (SINR thr ), through an iterative procedure found in [1][2][3] according to its SINR in its k-th subframe given by:…”

“…Additionally, the use of alternate polarization allocation (PA), as a mean to decrease the interference into the desired signal, is introduced in systems operating under LOS conditions [5]. Specifically, in [2] a heuristic scheduling mechanism along with a terminal classification procedure has been proposed for interference reduction. This concept is improved with the different scheduling mechanisms for odd and even sectors [3].…”

“…An increased effort is focused on the corresponding time domain radio resource allocation techniques (RRA) [2][3][4] in order to organize the total amount of interference. Additionally, the use of alternate polarization allocation (PA), as a mean to decrease the interference into the desired signal, is introduced in systems operating under LOS conditions [5].…”