Our Technology
HierComm’s technology for broadband wireless communications is represented at three levels of system operation:
- Network level
- Link level
- Equipment level
Network Level Design
Providing universal broadband wireless coverage of low density rural areas represents a significant challenge in network design. Hilly or mountainous terrains and the presence of large wooded areas make it difficult to reach many users with a cost effective network layout.
Conventional point-to-multipoint network architectures are usually constrained to serve line-of-sight subscribers. In some rural counties with relatively flat terrain and minimal forest cover, a conventional high tower, line-of-sight network architecture may be cost effective.
HierComm’s hierarchical hybrid network design approach has overcome barriers to universal rural coverage using a combined sectoral, mesh and linear network structure combinations. In a more typical county or region with mixed terrain and forest coverage, it may be required to add a second network layer of lower height, 60-foot high access points to provide an economic system design. Universal coverage, however, may still require arterial or sub-links to isolated groups of users. Finally, in some rural counties, the combined challenges of rough terrain and forest cover may require a linear network architecture in order to provide universal coverage in a cost effective manner.
HierComm’s network design technology offers solutions at all levels of wireless network design from conventional sectoral/cellular structures to mixed hybrid layouts and completely linear-oriented network architectures. In sectoral cellular network deployments, the design methodology specifies the optimal combination of high standing antenna towers and lower elevation access points to best achieve universal coverage in the region of interest. In hybrid network architectures, design algorithms select the best combination of direct and indirect radio wave pathways for universal, high performance radio coverage. Finally, in extremely rough terrains or with heavy forest cover, linear links are selected as the most cost effective pathways for optimal network architecture.
HierComm network designs currently in operation provide near-universal wireless connections up to 9 megabits per second symmetrical download and upload throughputs in a hilly area with fewer than 20 households per square mile. Universal coverage is feasible, as needed in a few isolated locations. Documented field tests have demonstrated immediate potential for service up to 20 megabits per second if demand for that level of service arises.
Link (Channel) Level Design
Having defined the network design most appropriate for the region of interest, link level design attempts to maximize access point range and channel throughput performance. A wide variety of factors must be considered in link design optimization for a particular frequency band including:
- Free space loss
- Antenna gains
- Atmospheric attenuation
- Tree cover obstructions
- Building obstructions
- Fresnel Zone clearance
- Transmit power limitations
- Receiver performance - with and without amplifiers
- FCC Regulations
Optimal link performance results from joint consideration of all of these variables in cost-effective link design. Each frequency band has its own technical, propagation, and regulatory characteristics. Each geographic area has its particular terrain pattern. FCC regulations typically allow for higher gains for antennas than transceivers for maximum transmit power for range extension in rural areas. Higher frequencies with greater free space losses also have smaller Fresnel zones for smaller tree clearance requirements. HierComm’s network link design process and technology has been developed specifically to maximize range and throughput of wireless networks in rural and low-density areas. The challenge is to optimize the range/performance combination that best serves the designated link and its users.
HierComm’s current deployments and pilot testing a county level public safety network has demonstrated sustainable local link connection throughput to 20 megabits per second, and backhaul links operating at 30 megabits per second. Our technology is currently capable of 60 megabit per second long-haul links if necessary.
Equipment Level Design
Innovations in new network architectures with their most desirable link specifications often require new or enhanced equipment components at the physical layer of system operation. A particular example is the linear-oriented network architecture. Changes in direction typically require redirection of radio wave pathways. New RF componentry had to be developed to serve such functions in a cost-effective way. HierComm has developed and is continuing to develop both hardware and software innovations to serve the particular needs of rural broadband wireless communications.
All HierComm equipment can operate with all wireless communications standards including WiFi 802.11x, WiMAX, and others. We employ standard, low-cost equipment modules and components to which we add our proprietary hardware, for a cost-effective, but very high performance solution.
Intellectual Property
Several patents are pending for HierComm’s network, link, and equipment level design innovations.
Broad-based Availability
Although we deploy our own designs and equipment previously un-served and underserved rural areas, we have done and will continue to do networks design and planning studies for county, state, and local governmental units, as well as private network builders and operators. Our equipment technology is also available to be deployed in public safety, community-owned, and privately owned wireless networks.