Home Engineering Broadband Wireless Communications for Railway Applications: For Onboard Internet Access and Other Applications
Public Cellular Networks Solutions
Studies and Project
The public cellular networks solutions are usually based on the use of several public cellular networks deployed over landmasses. The TAT integrates several links (up to 8in some cases) with different Mobile Network Operators (MNOs). Thereby, the TAT can manage the lack of coverage of one operator by supplying it with another one with better coverage. In the case of no coverage at all, a “gap-filler” solution can be used, as for the case of satellite solutions. Several solutions were deployed using cellular solutions. In , some field measurements are performed with the MNO 02 in UK. The objective was to evaluate TCP performance. The results show an average throughput at TCP level of 30 kbps with GPRS and 340 kbps with HSDPA. The authors pointed out the huge contrast with the theoretical throughputs announced by the operator (56 Mbps for the downlink, 22 Mbps for the uplink). In , two mobile Internet Service Provider (ISP) are compared in Korea. Each operator is operating two networks: 3G and 3.5G. Two scenarios are considered: an HST at 300 km/h and a mobile car at 100 km/h. Throughputs around 500 kbps at UDP level and 1 Mbps at TCP level, both in downlink and for both 3G and 3.5G are observed.
Nomad Digital , a specialist in on-vehicle ICT, provides wireless solutions to the transportation sector: trains, metros, trams and buses. The Company developed a wide range of solutions based on a scalable on-board IP platform, allowing passenger Internet access on board via Wi-Fi, and local contents, such as passenger information, infotainment and displays. The main solution is the NDConnect mobile router used in many rolled out solutions in the railway domain. Nomad Digital provides solutions based on public cellular networks only, and solutions based on the combination of cellular and WiMAX technologies. They are presented in the following.
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