Survey of secure handoff optimization schemes for multimedia services over all-IP wireless heterogeneous networks

In the very near future, we shall witness the coexistence of networks with heterogeneous link layer technologies. Such networks will naturally overlap each other and mobile users will need to frequently handoff among them for a number of reasons, including the quest for higher speeds and/or lower cost. Handoffs between such hybrid networks should be fast enough to support demanding applications, like multimedia content delivery, but also secure enough since different network providers are involved. This gets even more complicated considering that network providers may not simultaneously be multimedia service providers as it is the case today. In order to support security operations in a large scale the employment of an AAA protocol is mandated; however, this adds more delay to the handoff process. This article analyses and compares the prominent methods proposed so far that optimize the secure handoff process in terms of delay and are suitable for uninterruptible secure multimedia service delivery.