Project Title:

Project Title: Self-organising Smart Antennas for Wireless Networks

This project is to implement a network management tool for wireless networks that uses co-operative smart antennas for managing the radio resources in order to minimise the effects of congestion and to provide Quality of Service. This will be done in the context of the Macao environment.

This work builds on previous research athat has led to novel approaches for changing radio patterns from a mobile base station (or from a wireless LAN (WLAN) access point) in real time in a co-operative manner by applying the technology to real geographical layouts, in this case Macao. Recent research at QM has shown that the adaptive shaping has the potential to simplify network planning to cater to non-uniform demand, which is the norm in practice. This work will extend that network planning to realistic geographical environments, something that has not been done before. 

The proposal identifies exploitation routes for the technology that will benefit the Macao economy.

The exact nature of the collaboration is dynamic and autonomous, so it can be made dependent on load and the location of that load. The principle of operation is illustrated in Figure 1. If there is congestion in one cell then an exchange takes place between that cell and its neighbours in order to collaboratively optimise the radiation patterns to allow the congested cell to shrink and the neighbours to expand in order to fill any “holes”. This can be done in real time.

Figure 1: Principle of operation

A simulation result showing how the antenna patterns change in a homogeneous unconstrained network is shown in Figure 2. This taken from Queen Mary research shows how the shape of the real radiation patterns (solid lines) have changed in response to a traffic build-up. As hot spots form in a mobile network, the call-blocking rate increases, but by using intelligent geographic load balancing, congestion is much lower than in conventional networks, especially when there are hotspots rather than uniform increase. This scenario is particularly relevant to Macao, especially during events.

(a) Radiation patterns

(b) Performance evaluation

Figure 2: Results from simulation on homogeneous networks

From the map in Figure 3 it can be seen that the propagation characteristics in Macao (or indeed any other city) will depend very much on the geography and the layout of the cells. This is part of the normal radio planning of any mobile network since an operator needs to be able to take into account the effects of such factors as buildings, hills and open spaces; deciding where to base stations depends on this radio planning. This means that the radiation patterns are not simple circles on a rectangular grid, but depend very much on the local characteristics: for example, buildings create radio shadows.  The project will produce a system that take the geographic data into account, using sophisticated patch antenna technology, automatically control base stations' coverage to adapt the always changing patterns.

Figure 3: Map of part of Macao

The overall objectives are, therefore, to:

­       Apply the self-organising smart-antenna concept to city scenarios where there are geographical constraints.
­       Produce a working proof-of-concept network management demonstrator for managing radio resources using smart antennas for GSM/GPRS, WLAN and/or 3G.
­       Apply this to the geographical attributes of Macao.

Project duration: 24 Months