Basestation collaboration in Bluetooth voice networks

In the near future Bluetooth may be embedded into many different types of mobile and portable devices [IEEE Personal Commun. 7 (1) (2000)]. This connectivity will enable a variety of future picocellular services such as real-time voice and data [Specification of the Bluetooth System 1.0b., Bluetooth Special Interest Group, 1999]. In this paper, we consider several Bluetooth-based telephony access point designs. Since the number of SCO links per Bluetooth node is very limited, the designs consider the use of multiple overlapping Bluetooth basestations or module coverage areas. The first scheme is a direct implementation of the telephony profile where the Bluetooth basestations/modules operate independently, without any coordination. The paper proposes several schemes which use a variety of techniques for reducing the call blocking rate using real-time communication between the basestations or Bluetooth modules. It is shown that significant improvements in blocking performance are possible using this approach. A constraint on the design of high-capacity voice access points is the potential packet loss experienced by overlapping SCO transmissions. The paper includes a worse-case characterization and discussion of Bluetooth’s shortcomings in this regard.