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Pour plus d'information et pour les tarifs, nous contacter Partnership ALLSATCOM BELGACOM Allsatcom as a certified Belgacom partnership can propose all satellite services generated by Belgacom. Please find hereafter the presentation of the DVB RCS service for Internet accesses via satellite. 1. Belgacom DVB-RCS System Overview 1.1. Satellite Connectivity 1.1.1. Atlantic Bird™3 The Belgacom DVB-RCS service uses the Eutelsat satellite Atlantic Bird™ 3 at 5° West, offering a wide geographical coverage and a good elevation angle over the targeted region. The space segment is: · Non-Preemptible Capacity · Non-Restorable Capacity. 1.1.2. Central Site to Remote Sites The Belgacom DVB-RCS system uses the AB3 widebeam downlink coverage for the transmission from the central site to the remote sites.
Figure 2: AB3 – Widebeam Downlink Coverage This provides good coverage for the communication from the
central site in The coverage of the forward link may not be confused with the coverage of the DVB-RCS service. As the service consists of the forward and the return link, the coverage for the service is defined by a combination of the forward and the return link satellite coverage. 1.1.3. Remote Sites to Central Site For the connection from the remote sites to the central site, the AB3 spot beam uplinks are used. This allows achieving high data rates with relatively small antennas. The following figures provide an impression of the return link coverage.
Figure 3: Ku-Band Spot 1 Uplink Coverage The return link is DVB-RCS compliant and implements turbo code, encapsulation of IP traffic, dynamic bandwidth on demand capacity management and MF-TDMA. The default return link carrier will have a 512 kilobaud symbol rate and turbo coding at rate 6/7, resulting in a gross carrier rate of over 800 kbps and an IP rate of about 624 kbps. A typical configuration of the outdoor unit of the terminals is a 90cm antenna with a 2W amplifier. The exact outdoor unit configuration depends – among other things – on the location of the sites and therefore needs to be carefully selected. Figure 4: Ku-Band Spot 2 Uplink Coverage
Figure 5: Ku-Band Spot 3 Uplink Coverage 1.1.4. Indicative Summary of Coverage
Table 1: Indicative Summary of Coverage The table above provides an indicative summary of the provided coverage. This table does not represent any guarantee without further consultation with Belgacom. 2. Subscriber Service 2.1. Internet Access 2.1.1. Protocols and Applications The DVB-RCS system supports · ftp, http, https traffic: for web browsing and downloading · SMTP, POP3, IMAP: for email · ICMP: ping, .. · Simple UDP applications: Yahoo messenger, Odigo, … As the POP router has a fix public IP address and supports port forwarding, the system also supports additional services such as: · Web server · Mail server · IPsec server 2.1.2. Always On Once a terminal has been successfully installed, there is no subscriber intervention required to set-up connections between the hub and the internet. If traffic needs to go from the terminal to the central site (or vice versa) an IP connection will always be available. As the terminals are using a statically allocated public IP address, there is no need to go through an IP connection set-up. Traffic can be routed from and to the terminal at any time. To guarantee the proper functioning of the network, the subscriber shall keep the terminal powered at any time. The scheduler will regularly force a logon on layer 2 to test network and terminal health. To overcome some of the issues that are related to internet access via satellite, the system includes traffic enhancement services: · TCP acceleration: http and ftp traffic using the default protocol ports is accelerated · DNS caching: to avoid a double satellite hop for each name resolution · Web caching, Prefetching: to increase speed and avoid double downloads 2.2. Service Profiles Customers can choose from several predefined profiles. This will define the peak throughput the terminal can achieve on both forward and return link. The average throughput a terminal will reach depends on the load of the system and the traffic behaviour of the other subscribers he shares the bandwidth with.
Table 2: Overview of Available Subscriber Service Profiles for Managed Bandwidth 2.3. Customer Premises Equipment 2.3.1. Approved Terminal Supplier
We use the terminal DVB-RCS from Newtec
2.3.2. Outdoor Unit
The terminals will typically use a 90cm antenna with a 2-Watt SSPA and an LNB. Some sites may require a 120cm antenna and some may be served well by a 75cm antenna. L-band is used for the receive and transmit connection.
2.3.3. Indoor Unit & POP Router – Local Networking The IDU acts as the interface between the POP Router and the ODU and is a kind of satellite modem. The POP is the interface to the local network. On the local network, private IP addresses are used. On the interface towards the satellite (and the central site – connected to the internet backbone) a public IP address is used. The POP router has a PC Ethernet interface, which means the POP router can be connected: · To an end user PC via cross-connect cable · To a switch, router, firewall or other networking equipment via normal Ethernet cable
The basic services that are offered on the POP router are: · TCP acceleration · DNS cache, Web Cache, Prefetching · Port forwarding · DHCP server · Stateful Firewall
3. Belgacom Infrastructure 3.1. Teleport The Belgacom DVB-RCS Services uses the teleport facilities at the Lessive site. The DVB-RCS hub is connected to the Belgacom IP Transit network providing top class Internet connectivity. The connection to the IP network is fully redundant and has no single point of failure. The Belgacom IP transit network enables Service Providers to connect their customers to the rest of the world through global Internet network infrastructure. The |
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