SNEP:Satellite Network Emulation Platform

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SNEP (Satellite Network Emulation Platform) structure

Technology abstract

An Italian not-for-profit research organisation developed a real time Satellite Communication emulator to support the design of solutions based on network parameters and protocols analysis. The platform is composed of 5 units, each emulating a single component of a VSAT (Very Small Aperture Terminal) satellite environment. Developed under Linux OS, it offers a large set of functions for classifying and scheduling network traffic, simulating real time operations and interfacing with real networks

Technology Description

The real time emulation platform SNEP has been developed by an Italian research organisation to support the design of solutions based on network parameters (Quality of Service, latency, throughput) and protocols (TCP/IP, DTN) analysis. The platform is composed of five units, each emulating a single component of a VSAT satellite environment: • Gateway/Hub (SatGW), • Satellite (SAT), • Satellite Terminal (ST), • Two User Terminals (UT1 and UT2). Developed under Linux OS (kernel 2.6.20), it offers a large set of functions for classifying and scheduling network traffic, IP Security support and a large set of transport protocols (UDP-Lite, TCP Hybla, TCP Westwood+, TCP Reno, TCP Low-Priority). Demand Assigned Multiple Access (DAMA) functionalities rely on well-tested algorithms intercepting traffic from each Satellite Terminal. The traffic packets are processed according to a centralised DAMA allocation decision based on IP packet with a strategy close to TDMA one (Time Division Multiple Access), which is currently adopted in real DVB-RCS systems. Configurations with multiple terminals (at present up to 700) can be set up. SNEP can also be operated remotely through a web interface and allows hardware in the loop (real satellite, modems, switching, DPI, etc.). A typical example of output on real application traffic is given below. The picture refers to the estimated congestion window evolution, as a function of time, achieved from real traffic dump on the emulation platform using TCP new Reno and a typical DVB RCS system architecture.

Innovations & Advantages

Main advantages of the proposed emulator system with respect of other current solutions are: • Full capability for simulating and testing satellite communication systems on the ground • Real time operation • Star/mesh topology • Centralised control/management • Interfaces with real networks (Internet, Wifi, GSM, etc.) • Interconnection with other beds • Adjustable maximum rate for broadcast channel on forward link • Fixed or variable bandwidth allocation for the return link • Flexibility • Totally under control of the operator • Multiple standard adaptability (not only DVB RCS)

Further Information

Developed to support the design and validation of telecommunication satellite networks, applications and devices, the SNEP test bed can play a key role in other sectors, and therefore opens the road to a series of potential areas for tech transfer. The SNEP, indeed, has already been utilised in several other projects concerning:
-Telemedicine (real time experiment in tele-diagnosis with optimisation of the communication channel) 
-Optimum bandwidth allocation in presence of different user profiles (utilising a commercial DPI) 
-IP based dynamic bandwidth allocation 
-Optimisation of the configuration on IP platform of simultaneous transmission of Italian Lego-pro football championship matches 
-Optimisation of TCP protocols 
-Satellite sensor networks 
-Validation of DTN protocols 
-Validation of a commercial VoIP application under a satellite network 
-Vulnerabilities identification and implementation of countermeasures of heterogeneous networks 
-Assessment of SPDY protocol under a satellite network, etc.

Current and Potential Domains of Application

• Design of Internet architectures including a satellite segment,
• Validation of applications developed for multi-segment networks,
• Assessment of network devices (modems, routers, switches, DPI, etc.),
• Validation of data security solutions • Optimisation of resource allocation