SecureMesh™ WAN

The SecureMesh WAN provides a long-range, high-bandwidth, low-latency wireless mesh network capable of covering hundreds of square miles of the distribution grid. Each network provides up to 54 Mbps of seamless connectivity to grid devices as well as backhaul traffic from AMI collectors.

By connecting grid devices such as substations, voltage regulators, line switches, capacitor banks, and transformers, the SecureMesh WAN enables applications such as substation automation, distribution automation, SCADA, and workforce mobility. The network can also backhaul AMI collectors to enable secure private networking for advanced metering and can integrate distribution while maintaining end-to-end security through network virtualization and partitioning.

Network components include:

• SecureMesh WAN Gateway - WAN base station and “take-out point” that provides capacity injection
• SecureMesh WAN Extender - WAN mesh node that extends coverage from a Gateway to other Extenders and Connectors
• SecureMesh WAN Connector - WAN endpoints that provide standard Ethernet connectivity to devices

WAN Coverage

Because of its patented dynamic antenna pointing system, the SecureMesh WAN is regulated under point-to-point rules by governing bodies such as the FCC and ETSI, which permits the network to transmit at high power levels to provide both long-range and high-capacity connections. With dynamic point-to-point links, coverage can extend up to 10 miles between mesh nodes and, since the network also provides mesh networking, coverage can cascade over several hops – for instance, a 5-hop network can extend coverage up to a 50-mile radius from the Gateway take-out point.

WAN Capacity and Scalability

Each SecureMesh WAN mesh network includes a Gateway acting as the network “takeout” point. The Gateway interconnects a mesh network of Extenders, each acting as a relay node, and Connectors, which provide connections to endpoints. Each mesh network provides air data rates up to 54 Mbps per take-out point and capacity can be scaled in increments with each additional Gateway.

WAN Use of Standards

SecureMesh WAN radios use standard radios and standard OFDM modulation techniques.  The network dynamically and adaptively changes modulation based on the current conditions of the link, with rates ranging from 6 Mbps for the worst link conditions to as much as 54 Mbps for the best links.

The network provides Layer 2 Ethernet transport, allowing the communication of standard Ethernet frames to support any desired higher layer protocols, including full IP support – including IPv4 and IPv6 traffic – and a wide range of utility-related protocols such as DNP3, IEC 61850, SCADA-over-IP, and others. Peer-to-peer communications (i.e. substation automation equipment communicating directly to centralized substation automation applications) are fully supported without the need for data to be first processed at the headend. Ethernet connections can also support serial communication to SCADA devices through a standard serial-to-Ethernet adapter.

Network devices also provide the option for standard 802.11b/g connectivity to enable secure Wi-Fi at locations like the substations to enable a Field Area Network (FAN) for workforce mobility.

WAN Self-Healing Mesh Networking

When installed, each WAN node automatically establishes links with other WAN nodes and joins the mesh network. The SecureMesh WAN uses wireless mesh technology to extend coverage (modular expansion to bypass obstacles and terrain) and enhance reliability (dynamic routing and self-healing failover to ensure communications).  Typically, communications use links established upon deployment, but in case of link degradation, the mesh network provides route diversity and dynamic rerouting to maximize performance. In case of link failure, the network provides self-healing failover to autonomously reroute packets to active alternative paths across the mesh.  The network also provides self-healing failover in case of backhaul failure (for instance, a failure of an upstream router), in which case the mesh network autonomously self-heals and reroutes to an alternative backhaul through a different Gateway.

WAN QoS

The SecureMesh WAN allows Quality of Service (QoS) to be controlled through the mechanisms of rate shaping and traffic prioritization.  Rate shaping applies rules to limit the WAN capacity that a particular client device can consume and thus protects the WAN capacity available to other client devices.  Traffic prioritization, by contrast, ensures that each WAN node sends high-priority device traffic first and that only low-priority device traffic will be dropped if WAN capacity is momentarily exceeded.  Rate shaping thus protects against traffic flooding scenarios, while traffic prioritization minimizes latency and increases reliability for high-priority applications.

WAN Security

Security for mesh nodes and endpoint devices is supported throughout the communications network. Privacy and confidentiality are ensured through authentication and encryption throughout the network, including node-by-node authentication and encryption, encrypted intra-nodal control and status communications, and encrypted communication throughout the mesh.