A telecommunication system like an ISDN network comprises a great variety of software components. It includes software for switches, the terminal equipment (like a simple telephone) but also for the management of resources and the provision of high level services like time dependent call forwarding. Software for telecommunication systems like other software must be fast, robust and easy to main...

We describe our unifying architecture for multipoint-to-multipoint communications in ATM networks which meets the diverse requirement of group communications and permit a large degree of control on the multicast group. With an integrated use of a name space, the scheme allows scalable extension to large scale wide area multicast communications. We also enable exible control on routeing architec...

The placement of security functions determines which kinds of data they can protect against which kinds of attackers. Firstly, security functions are classified regarding their sphere of influence, e.g. between end points of communication associations (end-to-end) or end points of transmission lines (link-by-link). Next, we derive and illustrate restrictions and implications that limit the free...

This paper introduces a new coexistence study of the future WiMAX system and existing fixed wireless access (FWA) systems and investigates its feasibility. Spectrum emission mask as an interference mitigation technique is used as well as interference to noise ratio (I/N) of -6 dB as one of standard sharing criterion value at FWA systems recommended by international telecommunication union radio...

Our investigation is focused on the binary capacity improvement of the Down Link Channel in UMTS (Universal Mobile Telecommunication System). For a WCDMA (Wideband Code Division Multiple Access) system, the use of different channels at the same time, by many users, is possible because these physical channels are orthogonal to each other. For UMTS, these orthogonal codes are called “OVSF (Orthog...