Using session initiation protocol to build context-aware VoIP support for multiplayer networked games

Multiplayer networked games are the trend of the day. Receiving a major boost from various commercial ventures like Microsoft Xbox®[19] and Sony Playstation®[13], the networked gaming industry is set to grow dramatically. These multiplayer games allow geographically dispersed and possibly distant players to participate in a single game. In order to provide interaction amongst players in such environments, text messaging and recently, real-time voice interaction through VoIP is used. However, such interactions are mostly out-of-band (not based on game contexts), user-initiated and limited in operability, failing to exploit the entire potential and functionality of VoIP.In this paper, we present mechanisms and design of a prototype that allows game-context based VoIP communication between players. Thus, in addition to allowing players to talk to each other to coordinate teammates and activities (through a static team-based audio conference) as in some of the current systems, it supports communication among players based on shared contexts like the same physical location or room within the gaming environment. We use the Session Initiation Protocol (SIP) [14] to realize VoIP and describe mechanisms for building network gaming services using SIP. We also propose a sophisticated gaming scenario, in which VoIP is used to relay information about another player's distance and location with respect to the recipient, e.g. players farther away sound farther away.