Accessibility statement

Handoff for High Altitude Platform based Broadband Networks

High Altitude Platforms (HAPs) have the advantage of being able to deliver broadband capacities using a number of cells over a wide service area, typically up to 75km wide. However, until recently HAP communication system development has been slowed owing to the fact that there are no long-endurance unmanned HAPs available. To overcome this problem a number of active projects are now proposing cost-effective solutions based on fleets of stratospheric short-endurance manned HAPs. With this solution, fleet management and inter-HAP handoff strategies are required in order to maintain seamless connectivity to users on the ground. Handoff between cells on the same platform (i.e. intra-HAP handoff) has also shown to be beneficial to help combat platform attitude instability and better control of resource usage.

The project will initially examine the inter- and intra-HAP handoff mechanisms at the system level, looking at a number of different architectures, e.g.: (1) fleet of short endurance HAPs covering a service area; (2) single cellular HAP subject to attitude instability; (3) multiple HAP constellations. The project will then investigate how the handoff and radio resource management processes can be combined together, especially for options (2) and (3). The HAPs will operate in a pooled spectrum environment, so the combined radio resource management and handoff will exploit cognitive radio techniques.

A mixture of simulation and analysis will be used to assess performance, and it is expected that game theory and Markov analysis will be particularly important analytical tools. This work will integrate closely with other activities within the Group.

Key objectives

  • To understand how inter- and intra HAP handoff should be performed for different architectures
  • To develop appropriate handoff strategies, incorporating cognitive radio based techniques.

Outputs

  • An assessment of how intra-HAP and inter-HAP handoff can be achieved
  • Analysis and simulations of performance
  • Contributions to conference and journal papers.

Members

  • Shufeng Li
  • David Grace

Dates

  • October 2008 to
    September 2009

Research