Meeting Interactivity Requirements in Mobile E-Witness: An Experimental Study

This paper describes the design and development of a session-layer load balancing mechanism and its deployment in a mobile surveillance system named Mobile E-Witness (MEW), which we have developed (Ghini et al., Multimedia Tools and Applications, 37(3), 293–318, 2008). The load balancing mechanism proposed in this paper allows MEW to effectively meet interactivity requirements and it is based on an “early retransmission” technique that exploits the overall bandwidth provided by a number of heterogeneous (broadband and metropolitan area) wireless adapters incorporated in MEW. This technique anticipates a suspected unavailability of the adapters in order to avoid the effects of network congestion and guarantee continuity of the communication service and support for multimedia services such as IP telephony. We have carried out an experimental evaluation of the MEWprototype in order to assess its effectiveness inmeeting interactivity and responsiveness requirements. This paper summarizes our design and the principal results we have obtained from the evaluation mentioned above.