OVERVIEW AND BACKGROUND

In 2007, Silvus was funded by the US Defense Advanced Research Projects Agency (DARPA) to develop a new communications waveform which would satisfy the need for reliable, high-bandwidth video and data communications in harsh environments. Target applications included challenges such as: 

• Cluttered environments with a high degree of signal reflections (multipath) such as dense urban canyons 
• Non-line-of-sight (NLOS) operation involving the penetration of obstacles and/or making use of reflective signal paths to bypass obstacles 
• Vehicles and platforms with a high degree of mobility 
• Connectivity in the presence of interference and jamming 

MESH RADIOS 

The principle of a MESH Radio network is that multiple radio nodes bond together flexibly to form a fluid self-healing network that carries IP (network) data. A node can move around freely within a MESH-covered area and retain network connectivity to all other nodes. 

Silvus MN-MIMO (Mobile Net – Multi In Multi Out) Radios – Silvus radios differ from normal MESH radios. 

• They deliver exceptional point-to-point performance equal to or better than conventional Microwave platforms, but typically in less spectral bandwidth.
• They are available and deployed in Australia and New Zealand today in Public Safety, ISM and licensed frequency bands.  
• High Power amplifier solutions are available.  
• They have been designed for mobile deployment in temporary and semi-permanent installations rather than as a permanent infrastructure product. 
• They offer asymmetrical data rates of up to 100 Mbps. 
• They are “switch on and go”, requiring little or no management once configured for field operations. A Silvus MESH is a true peer-to-peer self-forming self-healing mesh with no master and no configuration requirements after initial setup. Members of the Mesh can join and leave freely Read More

PRACTICAL IMPACT OF SILVUS MN-MIMO ON EMERGENCY SERVICE OPERATIONS 

Mobile Ad-Hoc Networking (MANET or MESH) Radios (nodes) have the ability to link together to form a seamless IP network. The linking can occur either across the air (node to node), via the Internet (3G/4G, Satellite links, WiFi hot spots) or through a Local or Wide Area Network (NBN access point, Public Safety Mobile Broadband connection, terrestrial “hard” network). Any radio that sees any other radio will automatically form a link. The following diagram shows 5 nodes in a MESH. The colors indicate RF signal headroom between nodes, which determines the data capacity between those nodes. 

An IP packet sent into the Mesh is automatically routed by the best possible route at any given moment, with the radio adjusting its modulation and signal strength on a packet-by-packet basis to optimize the overall network. The benefit of this is that any node can move around in an area covered by other nodes, and they will all form a seamless network to transport the traffic from that node to wherever it needs to go. 

In order to cover a large area, it is only necessary to place a succession of nodes (for example in water proof cases, battery powered with Solar charging) to cover the area required, with one of the nodes connected back to headquarters. Operators can move freely around between them and they will remain connected to headquarters. Any IP requirement can be met in the covered area – Mobile computers, tablets, smartphones, IP Communications systems... A private, secure cellular network has been established. It is important to note that the “MESH” can be extended to cover any interconnected areas - across the state, country or globe – as long as there is an appropriate network connection to be had. The network is secured using AES Encryption to Military standards. In this way the MESH forms a seamless extension to the headquarters WAN – without the operator having to do anything but turn on a node and watch for a green light. 

If the connection to headquarters is unavailable, the local network is still in place – allowing members of a field group to remain connected to each other even whilst disconnected from HQ. A local Command and Control unit can therefore still extend all of its network capabilities to members of an attached field group even if no Headquarters connection is available.

A mobile integrated IP network connected to HQ via mesh, helicopter relay and local backhaul points 

APPLICATION EXAMPLE - MN-MIMO FOR PUBLIC SAFETY AND EMERGENCY SERVICES 

• MN-MIMO is uniquely suited to address many of the key requirements of Emergency Services, including: 
• Operation in remote areas without reliance on public infrastructure 
• Transmission in dense urban environments, including NLOS and penetrating in/out of buildings 
• Operation in a variety of frequency bands 
• Increased data rates to support high resolution video imagery (up to 100 Mbps) 
• Low end-to-end latency (<10mS per hop) 
• Improved spectral efficiency (more bits per second per hertz) and simplified frequency coordination (single RF channel shared by multiple users) 
• Bi-directional capability supporting either symmetrical or asymmetrical traffic 
• Flexible network infrastructure to facilitate end-to-end IP workflow 
• Establishing a secure private cellular network – the system is secured by AES 128/256 encryption. 

Silvus’ MN-MIMO technology can be leveraged to provide a high performance IP network between 2 or more assets, including: 

• Remote camera – MN-MIMO can be used for the ‘first mile’ link to connect a remote camera to: 
  • Command and Control Vehicle 
  • Portable point-to-point microwave or high powered MN-MIMO link 
  • 3G/4G modem (for instances where camera is in a building or area with poor cell reception) 
  • BGAN or other satellite terminal 
  • WiFi hotspot 

Since the link is bi-directional, latency is low, and throughput is significant, MN-MIMO is a single radio solution suitable for the transport of video, return video and communications. 

• Command Vehicles – Command Vehicles can act as a relay, connecting field units to each other and to Headquarters. 
• Helicopters and UAVs – MN-MIMO is well suited for long range airborne links. Helicopters and UAVs can also be used as a relay for Command and Control vehicles and ground-based assets to provide coverage in areas inaccessible via terrestrial links. 
• Headquarters – Central receive configurations are available with high gain directional or omnidirectional antennas 
• Point-to-point links – MN-MIMO facilitates bi-directionality and high bandwidth, making it an ideal solution for the transport of video, audio, and data over portable point to point links 
• Strategic receive sites – Multiple receive sites can be installed at strategic locations to provide blanketed ‘cellular’ coverage of a large sprawling metropolitan area 
• Tactical receive sites and “reach points” – Radios can be temporarily deployed at hotels, coffee shops, Fast Food outlets, private residences, businesses, stadia, hotels or any other location with an internet or WAN connection. This provides the ability to setup ad-hoc receive sites to cover incidents that occur outside the range of strategic receive sites. 
• Field operatives – an EMERGENCY SERVICE member equipped with a Silvus Radio can not only benefit from Push-to-Talk (PTT), video transmission and reception and WiFi connectivity themselves, but can also provide access to these facilities for their team members. 

GPS Location Tracking

Each StreamCaster Radio has provision for connection to a GPS antenna. When so connected, the radio will make available a map of its location to any connected Net Management client:

Maps may be either preloaded into each radio, or downloaded in real time via an available Internet connection. 

The SC4400 and SC4200 are also available as OEM board sets for integration into custom enclosures such as active Radio/Power amplifier/Quad Antenna combinations or for permanent integration into vehicles or road kits. 

FLEXIBILITY IS THE KEY 

Silvus meshes build themselves out of any nodes that are within RF range of each other or connected by LAN, WAN or Cellular. Every node acts as a relay point for every other node. The implication is extreme simplicity in setup – antenna placement is really the only field consideration that need be trained. Field operators and volunteer’s equipment is typically either cabled or connected by WiFi to the resulting Mesh network. 

Nodes can be configured in many formats to achieve the desired results, some examples being: 

Vehicle Unit – an SC4480 with higher gain Omni Antennas mounted to the roof of a vehicle or boat, and providing an anchor point for the rest of a local Mesh as well as a hardwired access point for management systems. The local connection systems (3G/4G modems, Satellite systems etc.) can also be housed in the vehicle. 

Portable Node – a self-contained unit with integrated Battery, optionally with Solar Charger, that can be temporarily placed in any location to either provide a relay, semi-permanent monitoring point, or temporary access point to a backhaul network. 

Personal Unit – with or without Video, WiFi Access Point, PTT, GPS locator. Typically one unit deployed for every other person in a field team, with the balance of the team accessing the Mesh via WiFi. 

Tower System – permanent or temporary towers, with high gain sector antennas and/or amplification, providing area coverage for mobile teams.