African Telecoms Assisted By World Telecom + ESA

Telecom operators across Africa and the Middle East can now benefit from new technology developed with the assistance of the European Space Agency (ESA). World Telecom Labs, a Belgian-based developer of Voice over IP (VoIP) equipment for telecom operators, developed this technology through ESA’s Research in Telecommunications Systems (ARTES) program. The project’s objective was to address the difficulties of carrying VoIP traffic over shared satellite services, primarily DVB-RCS, to result in a commercially saleable device allowing telecom operators to deploy a range of satellite-based commercial services. The platform used for this development was WTL’s existing IPNx switch. Modifications needed to be made in order for it to become suitable for satcom operators by adapting WTL’s patented Network Optimisation Protocol (NOP). Using WTL’s NOP bandwidth-saving technology will typically cut the cost of satellite bandwidth in half without sacrificing quality. This technique packs multiple VoIP voice samples into a single IP packet. As the samples are not modified, quality is unaffected but, on multi-call links, significant savings are made on the packet overhead. Also, as single samples are taken from each active call rather than queuing multiple samples from the same call, delay is not increased.

As the focus of the project was to create commercial benefits, a live customer network was to be installed and tested. The client chosen for this pilot was Xplorium, an international wholesale VoIP carrier with a presence in Europe, the Americas, the Middle East and Africa. Xplorium’s specialities include carrying the international traffic of Global System for Mobile Communications (GSM) operators. In a number of locations the traffic is carried via satellite and this has given rise to concerns about the voice quality and the efficiency of transmission. The first operational link used for the pilot was between Gambia and the client’s NOC in Paris with a capacity for 360 optimized VoIP calls (equivalent to 12 E1s). The trial was successful by demonstrating high voice quality and confirming that significant bandwidth savings were actually achieved. As a result, the pilot was soon followed by deployments in a number of other African locations, with the traffic again sent to the Paris hub.