Rural operators face unique challenges in providing cost-effective broadband access. 3.65 GHz, a spectrum used by few current operators, offers a unique land-grab opportunity. The combination of WiMax and the 3.65 GHz spectrum makes possible low-cost deployments that overcome the traditional challenges of the rural market and public spectrum space.
The difficulty with establishing broadband service in a rural market can be summed up by the common saying: "If it were easy, everyone would do it." Rural areas are everything that urban ones are not. No readily available infrastructure exists on which to build an access network. No dense population justifies the cost of adding a new infrastructure. Average income levels are less than those of urban households. All this means that two things inhibit the introduction of broadband service in rural areas: high infrastructure costs and low rates of return.
Nevertheless, it is astonishing to imagine any region in the United States that cannot provide its citizens with basic commodities. Like electricity, running water and telephone connectivity, broadband is now considered a commodity. So how do operators bring broadband to rural regions?
One major advantage rural operators have is the availability of government subsidies. In the last few years, urban broadband market penetration has grown to 20 percentage points greater than rural broadband market penetration. A surprisingly large area of America has fewer than three service operators. These areas correspond to under-served rural areas.
This technology divide in modern America has not gone unnoticed. Large funding initiatives have been established by many government organizations for the purpose of bridging this gap. Both the FCC and USDA recognize this problem and have allocated funds to rural operators. The FCC has established the Broadband Fund, committing $300 million per year to support the construction of new high-speed networks. The USDA's Broadband Access Loan program has allocated over $1.2 billion so far for the construction, improvement and acquisition of facilities providing broadband service to eligible rural communities. Operators can use these funding programs to subsidize rural deployments and generate profit.
Laying down additional fiber or updating old copper lines is a costly endeavor. This is aggravated by the topology of many rural areas, where impassible terrain makes new trenches impossible. Many areas are protected lands and have stringent right-of-way proscriptions. What's more, the population of rural areas can be extremely sparse, and residences may be miles from each other.
In areas where trenching is possible, the cost can still be prohibitive. Three common methods for laying new conduit exist:
* Stringing aerially on existing poles ($3 to $6 per meter)
* Burying in existing conduit ($7 to $10 per meter)
* Burying in new trenches ($35 to $200 per meter)
Laying new conduit over several hundred square miles can cost hundreds of millions of dollars.
In addition, right-of-way costs must also be added to the formula in many instances:
* $1 per pole per month
* $0.50 per strand of support wire between poles
* $1 per meter of existing conduit
This can add several million dollars in additional deployment costs.
So how can operators overcome this prohibitive cost? The simple solution is to deploy wireless technology. By concentrating on aggregation towers serving large areas, infrastructure costs can be reduced by factors of one hundred to one thousand.
Two major roadblocks have prevented successful wireless deployments on a wide scale: the lack of cost-effective spectra and the unavailability of supporting radio technology. An operator who decides to deploy a wireless solution prefers to do so over a licensed spectrum. A licensed spectrum gives its operator complete exclusivity on its airwaves, avoiding contention with other operators that would otherwise degrade performance. The problem with licensed spectra, however, is their cost. Most commercial licensed spectra are purchased in auctions held by the FCC. Because they sell to the highest bidder, these licenses typically run to billions of dollars, an expense that's just not realistic for the typical rural operator.
The other alternative is to use a public spectrum. Public spectra can be used by anyone for any purpose so long as the equipment used meets FCC emissions requirements. This allows an operator to offer wireless service without paying the expenses of licensing a spectrum, but the downside to public spectra is their lack of regulation. Because anyone can use the public spectrum, many other devices can interfere with operators' services. Interference from devices such as Wi-Fi points of access, wireless home phones and even microwaves can degrade signal quality.
Most operators using the public spectrum form consortiums with other local operators in an attempts to avoid these problems by coordinating frequency use. However, anyone can use public spectra, causing interference despite careful planning by consortia.
The 3.65 GHz spectrum band presents a unique opportunity for operators. The spectrum can be purchased for a nominal FCC registration fee. The FCC registration database helps provide some level of protection and coordination between multiple operators; and for 0.000001% of the cost of a licensed spectrum, 3.65 GHz is a steal.
Subhead: Solving the technology issue
The last part of the rural access solution is the selection of wireless technology. Until recently, few efficient, high-bandwidth wireless solutions have been available. Because of the difficulty in obtaining spectra, operators want to maximize their revenues by providing the maximum amount of service possible on their channels. The level of service is restricted by the available bandwidth; this is one of the reasons operators select WiMax.
IEEE 802.16-2004 fixed WiMax has one of the highest spectral efficiencies available. WiMax is capable of 3.2 bits/Hz. By way of contrast, Wi-Fi 802.11g has a spectral efficiency of only 1.2 bits/Hz. WiMax squeezes more bandwidth out of less spectrum.
Another major advantage of WiMax is that it is a non-line-of-sight (NLOS) technology. This means that it is more tolerant than other technologies of physical interference that could otherwise block or reflect wireless signals. This allows WiMax signals to propagate better than those of line-of-sight (LOS) technologies such as Wi-Fi.
A key strength of WiMax is its support for over-the-air quality of service (QoS). WiMax offers several service types that allow traffic to be customized to the application. These service types allow the bandwidth and traffic to be shaped to various broadband applications and allow operators to offer several types of differentiated services.
There are also a wide variety of WiMax equipment types. Various base stations and customer premise equipment (CPE) allow operators to customize deployment to suit their needs. One of the most appealing aspects of WiMax products is the self-install CPE. This indoor CPE can be mailed to the customer and self-installed, eliminating the costly truck-roll associated with other wireless or wired solutions.
By using the 3.65 GHz frequency, problems with public spectra are overcome and (through the FCC's registration database) a means to coordinate with other operators is available. In combination with robust WiMax technology, this allows operators to provide superior service, finally making rural broadband access a reality. Fujitsu WiMax technology enables rural operators to overcome these major obstacles by providing a WiMax solution in the newly defined 3.65 GHz spectrum.
Kai Mao (firstname.lastname@example.org) is principal product manager at Fujitsu Network Communications. He has over 12 years of experience in wide-area networking and represents Fujitsu as a contributing and voting member of the WiMax Forum. Mao holds a BSc in electrical engineering from the University of Western Ontario, London, Ontario, Canada.