MSAT network architecture

The Mobile Satellite (MSAT) communications system will support mobile voice and data services using circuit switched and packet switched facilities with interconnection to the public switched telephone network and private networks. Control of the satellite network will reside in a Network Control System (NCS) which is being designed to be extremely flexible to provide for the operation of the system initially with one multi-beam satellite, but with capability to add additional satellites which may have other beam configurations. The architecture of the NCS is described. The signalling system must be capable of supporting the protocols for the assignment of circuits for mobile public telephone and private network calls as well as identifying packet data networks. The structure of a straw-man signalling system is discussed

Market assessment of photovoltaic power systems for agricultural applications in Morocco

Results of a month-long study in Morocco aimed at assessing the market potential for stand-alone photovoltaic systems in agriculture and rural service applications are presented. The following applications, requiring less than 15 kW of power, are described: irrigation, cattle watering, refrigeration, crop processing, potable water and educational TV. Telecommunications and transportation signalling applications, descriptions of power and energy use profiles, assessments of business environment, government and private sector attitudes towards photovoltaics, and financing were also considered. The Moroccan market presents both advantages and disadvantages for American PV manufacturers. The principle advantages of the Moroccan market are: a limited grid, interest in and present use of PV in communications applications, attractive investment incentives, and a stated policy favoring American investment. Disadvantages include: lack of government incentives for PV use, general unfamiliarity with PV technology, high first cost of PV, a well-established market network for diesel generators, and difficulty with financing. The market for PV in Morocco (1981-1986), will be relatively small, about 340 kwp. The market for PV is likely to be more favorable in telecommunications, transport signalling and some rural services. The primary market appears to be in the public (i.e., government) rather than private sector, due to financial constraints and the high price of PV relative to conventional power sector

INDICATIONS FOR SIGNALLING THE PRESENCE OF A PRIVATE 5G NETWORK

Private 3rd Generation Partnership Project (3GPP) fifth-generation (5G), or Private 5G (P5G), networks are local networks or local area networks (LANs) that are built using 3GPP 5G wireless technology to carry traffic within a specified area, such as within an organization, on a campus, or within an industrial space. A growing number of enterprise and public sector companies are considering building their own P5G networks to address their need for clean spectrum, high bandwidth, low latency, higher availability, and increased visibility. With the introduction of P5G networks, there may be scenarios where both Wi-Fi and P5G networks are present in the same area. When both technologies are available in the same location, current User Equipments (UEs) are designed and configured to prefer the Wi-Fi network for data connectivity. However, there are circumstances that would benefit from the use of P5G connectivity instead of a Wi-Fi network. Techniques are presented herein that support three new mechanisms to inform a UE about the presence of a P5G network and list the services that could benefit from using such media access instead of Wi-Fi when the UE enters the P5G network coverage area. The first mechanism is based on Bluetooth Low Energy (BLE) beacons broadcasted by Wi-Fi access points (APs), the second mechanism leverages stand-alone BLE tags, while the third mechanism employs Internet Protocol version 6 (IPv6) router advertisement (RA) options. The different mechanisms require minimal changes to existing devices, as the underlying technologies that are used are already implemented on both commercially available access points (APs) and UEs. In addition, such mechanisms provide several benefits in terms of power savings and the possibility of immediately transitioning to a P5G network when coverage is available

Securing route optimisation in NEMO

Third International Symposium on Modeling and Optimization in Mobile, Ad Hoc,and Wireless Networks. 4-6 April 2005. Riva del Garda, Trentino, ItalyThe network mobility (NEMO) basic support protocol enables mobile networks to change their point of attachment to the Internet, while preserving established sessions of the nodes within the mobile network. When only a nonnested mobile network is considered, the so-called triangle routing is the main problem that should be faced. In mobile IPv6, the route optimisation mechanism solves this problem, and the return routability mechanism aims to limit the security concerns originated because of the route optimisation. Nowadays return routability is considered a weak solution (i.e., based on strong assumptions). In this article we explore different approaches to route optimisation in NEMO and we devise how to adapt some of the terminal mobility solutions to a NEMO environment, where, as we propose, a delegation of signalling rights from the mobile network node to the mobile router is necessary.Publicad

Towards transnational interoperable PPDR communications: the European ISI cloud network

The European Council has been stressing the need for interoperability among technologies used for Public Protection and Disaster Relief (PPDR) communications across Europe for a long time. Nevertheless, while the introduction of TETRA and TETRAPOL technologies in the last two decades has increased the possibility to talk cross agency internally in a country, cross border communication for the public safety forces is not well solved as of today. This paper describes the communications interoperability solution that is being developed in the framework of the ISITEP project. This solution, referred to as the European Inter-System Interface (ISI) Cloud Network, aims to integrate the PPDR national/regional infrastructures to allow migration (i.e., roaming) and communication services between networks within a secure framework. The ISI Cloud Network involves, among other components, the specification of a new ISI interface to be deployed over IP transport networks and the development of a number of different gateways to cover the use of TETRA and TETRAPOL technologies as well as the use of legacy TETRA ISI by some networks.Peer ReviewedPostprint (author's final draft

Denial of Service in Voice Over IP Networks

In this paper we investigate denial of service (DoS) vulnerabilities in Voice over IP (VoIP) systems, focusing on the ITU-T H.323 family of protocols. We provide a simple characterisation of DoS attacks that allows us to readily identify DoS issues in H.323 protocols. We also discuss network layer DoS vulnerabilities that affect VoIP systems. A number of improvements and further research directions are proposed

Wireless internet architecture and testbed for wineglass

One of the most challenging issues in the area of mobile communication is the deployment of IPbased wireless multimedia networks in public and business environments. The public branch may involve public mobile networks, like UMTS as 3G system, while the business branch introduces local radio access networks by means of W-LANs. Conventional mobile networks realise mobile specific functionality, e.g. mobility management or authentication and accounting, by implementing appropriate mechanisms in specific switching nodes (e.g. SGSN in GPRS). In order to exploit the full potential of IP networking solutions a replacement of these mechanisms by IP-based solutions might be appropriate. In addition current and innovative future services in mobile environments require at least soft-guaranteed, differentiated QoS. Therefore the WINE GLASS project investigates and implements enhanced IP-based techniques supporting mobility and QoS in a wireless Internet architecture. As a means to verify the applicability of the implemented solutions, location-aware services deploying both IP-mobility and QoS mechanisms will be implemented and demonstratedPeer ReviewedPostprint (published version

The price of re-establishing perfect, almost perfect or public monitoring in games with arbitrary monitoring

This paper establishes a connection between the notion of observation (or monitoring) structure in game theory and the one of communication channels in Shannon theory. One of the objectives is to know under which conditions an arbitrary monitoring structure can be transformed into a more pertinent monitoring structure. To this end, a mediator is added to the game. The objective of the mediator is to choose a signalling scheme that allows the players to have perfect, almost perfect or public monitoring and all of this, at a minimum cost in terms of signalling. Graph coloring, source coding, and channel coding are exploited to deal with these issues. A wireless power control game is used to illustrate these notions but the applicability of the provided results and, more importantly, the framework of transforming monitoring structures go much beyond this example.Comment: Proc. of the 4th ACM International Workshop on Game Theory in Communication Networks, 201