User Manual

Network Topologies

The SkyPilot Carrier-Class Broadband Wireless System supports point-to-point, point-to-multipoint and mesh topologies. An

operator has the flexibility to start with a simple point-to-point/multipoint configuration and add SkyExtenders as subscriber demand

requires to create a more robust mesh topology over time.

Point-to-Point/Multipoint

In a typical point-to-multipoint configuration, a SkyGateway is installed on a cell-tower, tall building or other height-advantaged

location. All SkyConnectors deployed within range then communicate with the SkyGateway’s centralized location. Note that the

compact nature of the SkyGateway means that smaller networks can easily be supported; simply install the SkyGateway at any

appropriate location where wired or wireless backhaul can be provided.

This simple, omnidirectional configuration can be extended outward in any direction using SkyExtenders. The links or “hops” from

the central SkyGateway to the SkyExtenders can be point-to-point or point-to-multipoint. At some point (no pun intended), the

network topology becomes a mesh with the potential for multiple, redundant links among SkyExtenders and one or more

SkyGateways.

Mesh

A SkyPilot mesh network utilizing SkyExtenders offers a number of significant advantages over point-to-point and point-to-

multipoint topologies:

• Coverage

In a point-to-multipoint wireless network, each subscriber must link to a single, central base station location. In most

deployment scenarios, large buildings, hills and other line-of-sight obstructions result in a lack of service availability to a large

percentage of prospective subscribers. The SkyPilot mesh topology offers service to any subscriber within range of the

SkyGateway(s) or any SkyExtenders. This topology enables subscribers to “connect around” obstructions that would defeat a

point-to-multipoint system, and serves to extend the overall range or reach of the network.

• Capacity

The SkyPilot system supports variable modulation rates, with a continuous link optimization process that selects the highest

data rate possible for a given link. As SkyExtenders are added to the network and the mesh grows, the number of possible

links increases and the average distance between them can decrease, which together result in increased modulation rates and

greater overall network capacity.

• Redundancy

The SkyExtenders automatically establish multiple links with other SkyExtenders and/or SkyGateways. Though only a single

link per node is used for routing traffic at any moment in time, the remaining links are retained and available for immediate use

in the event of a primary link failure or degradation. This level of redundancy extends throughout the mesh where multiple

SkyGateways can be deployed in a load-balancing arrangement with automatic failover.

• Spectral Efficiency

All communications throughout a SkyPilot mesh are directed and coordinated (see sections on RF Management and the

SkyPilot Synchronous Protocol), allowing for greater spectral re-use to achieve better performance and enhanced

scalability.

Mesh Routing

All subscriber traffic is routed between a SkyGateway and the subscriber’s node (a SkyConnector, SkyExtender DualBand, or

SkyExtender providing subscriber connectivity). While traffic can be exchanged among nodes within the mesh, it must ultimately be

forwarded by a router or switch to an external network, which also adds an additional level of security. The SkyPilot system

software allows for the optional switching of subscriber traffic by a SkyGateway.

The SkyPilot mesh routing protocol, which is independent of the networking interfaces at both the SkyGateway and the

SkyExtender/SkyConnector nodes, utilizes a cost-based algorithm that factors link capacity (modulation levels) and hop count.

Each SkyGateway periodically generates a routing cost message. Every directly-linked SkyExtender and SkyConnector receiving