6. BLUETOOTH BASED AD-HOC NETWORKS FOR VOICE
Bluetooth (IEEE 802.15.1) is a short-range wireless communications technology originally intended
to replace the cables connecting portable and/or fixed devices while maintaining high levels of security. It
operates at a frequency of 2.4GHz with bandwidth of few Mbit/s. Each interface can have 7 simultaneous
connections. One distinguishes three classes of Bluetooth interfaces depending on their transmission power and
potential range.
Bluetooth is thus a technology for short-range networking of few elements. In general, there is a
human mediated association of the devices: the person wanting two devices to interoperate has to physically
manipulate the devices in order to allow the association. A typical example is a user wanting to pair his handsfree
apparatus with a mobile phone.The technology was originally designed for short range personal area
networks, but the widespread use of Bluetooth interfaces in consumer portable electronics has opened the
Door to new forms of exploitation.
Transmission [FKW02] can be used for transmitting audio using synchronous connection oriented
(SCO) links. When we use Blue-tooth as a physical layer for a MANET, we will have several constraints like
connected-oriented nature of bluetooth, no broadcast capability, restricted number of connections, long
connection set-up time etc. To overcome these problems, a new protocol Bluetooth Scatternet Routing (BSR)
has been developed. It is a reactive routing protocol similar to AODV or Dynamic Source Routing (DSR) but
keeps additional information on the state of links and tries to avoid long delays due to inquiry or connection
setup. The first approach tried to make P2P networking feasible in a mobile environment is JXME[Aro02]
based on JXTA. JXTA technology developed by SUN micro systems is a set of open, generalized peer-to-peer
protocols that allows any connected device e.g. cell phone to PDA on the network to communicate.