Enhancing Mobile E-Witness with Access Point Selection Policies

This paper describes the Mobile E-Witness (MEW) surveillance system which we have extended to incorporate in it an advanced access point selection mechanism. The mechanism selects dynamically the best access point among those reachable in the metropolitan areas where MEW operates. The selection policy is based on both the strength of the access point´s signal and the traffic on the wireless communication channels. The selected access points are associated with the wireless network adapters available on board of MEW Mobile Sensor devices, thus allowing these devices to reliably and continuously transmit multimedia data streams to a remote storage center for future replay. We have carried out an experimental evaluation of the extended MEW prototype in order to assess its effectiveness in coping with such limitations as scarce wireless communication resources. The results of this evaluation are discussed in this paper and show the adequacy of our approach.