ND SatCom SKYWAN IDU 7000, Руководство пользователя

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2010-10-26 Network Design and Engineering Guide 131
Summary and Design Implementation
5 SUMMARY AND DESIGN IMPLEMENTA-
TION
In chapter 2 the task has been discussed, how to design SkyWAN carriers to be optimally sized
to fulfill customer traffic requirements. The major result of this calculation are the modem data
rates for the individual SkyWAN carriers (which are used as input for the link budget calcula-
tion), to determine the optimal carrier modulation and coding and the required outdoor unit
equipment. This task has been described in chapter 3. The result of the latter calculation may
trigger a reconsideration of the carrier design for the following reasons:
- There is a weak dependency of the TDMA overhead on the modulation and coding. That
means that selecting a different modulation and coding may require an adjustment of the
modem data rate.
- The link budget calculation may lead to the conclusion that a further splitting of SkyWAN
carriers would allow a more optimized usage of the satellite transponder. In this case a new
traffic and TDMA calculation with more carriers might be required.
The final result of the carrier and outdoor unit will determine the following network properties:
- Hardware:
- Antenna type for each site.
- Amplifier type for each site.
- IDU hardware: Sites with two demodulator boards, master sites with FPG board.
- Configuration:
- SkyWAN satellite link master and network parameters according to TDMA calcu-
lation result.
- SkyWAN home channel settings.
- SkyWAN satellite link station parameters according to used ODU hardware (Tx
and Rx path local oscillator frequency and spectrum inversion, Monitoring and
Control protocol parameter).
Additional input may be required from the satellite operator, especially carrier frequencies for
the SkyWAN channels.
The second part of the engineering task is the application engineering which has to take into
account both the customer’s requirements and networking environment and the SkyWAN IDU
and FAD (if applicable) properties. The SkyWAN functionalities concerning IP and Frame Re-
lay networking have been discussed in chapter 4 of this guide. The following parameters have
to be defined for the data networking functionality.
- IP Networking:
- IP addresses of the SkyWAN IDU interfaces according to the customer’s IP ad-
dressing scheme.
- IP routing: Definition of static IP routes or OSPF interfaces for dynamic routing
according to the customer’s IP network topology.
- Management access: Definition of IP management access parameters to allow
remote management from central SkyNMS stations.
- Multicast IP forwarding: If required, definition of IP multicast forwarding tables for
each IDU which is involved in IP multicast forwarding.
- IP Quality of Service: Definition of IP Forwarding Aggregate tables according to
the required service levels and IP networking topology.
- Additional IP features like TCP acceleration and header compression must be de-