Summary of De Veciana and Zemilanov's Work

Papers
1- Main conference paper.
2- Book Chapter describing the derivations.

Scenario:

* A WAN operator who aims to give universal coverage.
* A WLAN operator who aims to give local high performance coverage.
* Users deciding independently.

Modeling:

* Stochastic geometry is used to model both the position of WAN an WLAN AP's, and users.
* The users make greedy decisions maximizing a given utility function.
* Utility functions are either proximity based or capacity based.
* Proximity based changes with the distance.
* Capacity takes into account the delay of an file download assuming Processor Sharing discipline is used at the base station. The delay is modeled as the delay of a M/G/1-Processor Sharing queue. The more number of users, larger the delay.

Results

* The utility function that include both proximity and capacity reaches a global equilibrium.
* The performance metrics are the average delay over the entire user population, and average worst case delay averaged on different WAN service zones. The congestion sensitive mechanisms give %300-%600 increase over the proximity only metrics.
* Furthermore, the congestion sensitive utility functions reduce the spatial load fluctuations, and are able to reduce the back-haul bandwidth required for the WLAN's this is the largest expenditure for these type of access networks.

Notes

* The congestion sensitive utility function, based on the M/G/1/PS is taken from Sem Borst's paper. Borst in turn takes this from Telatars 1995 paper.