Cable's Wireless Options
One of the classic questions new marketing students are taught to ask is, "What business are we in?" The answer often used by instructors as an example that shows how to survive and dominate in your market is one given by a circa 1950s AT&T CEO, who stated that it was not telephones, but communications, that drove his business plan. When you apply the same perspective to our business, it’s easy to see why wireless solutions have to be a critical part of cable’s future.
Wireless is, however, a far-reaching technology, and it doesn’t make sense for every cable company to implement every wireless alternative or to use it for every application. A way to sort things out is to segment technology by the problem it solves. In general, wireless is not the technology for big screen video – although there’s enough capacity to handle distribution of a video signal, more revenue can be realized by sharing that capacity among multiple subscribers using this media for data and voice applications. At a high level, there are four applications where wireless adds customer solutions to a cable plant: wireless access, wireless extensions, mobility applications, and fixed-mobile convergence (FMC). Another parameter is whether the wireless technology is compatible with a cable operator’s DOCSIS-based plant. There are several vendors that offer solutions in one or more of the four applications, but only a handful are DOCSIS-based. Wireless access Wireless access is a way to supplement landline-based cable plant in rural or sparsely settled geographies. The architecture consists of a base station transceiver, connected to a tower-mounted antenna, a radio link operating in licensed or unlicensed bands ranging from 770 MHz to 3.5 GHz, and a subscriber antenna and transceiver.
The ARRIS WiDOX technology is an example of a wireless access product based upon DOCSIS technology. At the subscriber location, a DOCSIS-based wireless cable modem or embedded multimedia terminal adapter (EMTA) provides the interface to data, voice, or video on demand (VOD). At the base station, the C3W cable modem termination system (CMTS) is also DOCSIS-based and provides the interface to the PacketCable network.
Angelo Bione, WiDOX director of product development, notes that WiDOX is an alternative to using WiMAX for wireless access, but is a different architecture that can have cost advantages. "WiDOX operates at higher transmitted power, using one tower to provide subscriber coverage, whereas WiMAX would require multiple towers," said Bione. A WiDOX base station typically transmits in the range 5-40 Watts and could be located at a headend or hub. Depending on the frequency used for the link, WiDOX can be used in areas where foliage blocks the path. Transmission occurs on a pair of 6 MHz channels, one for upstream and one for downstream. Wireless extensions A wireless plant extension is another way to extend market coverage, albeit to a smaller geographic area than with wireless access. A typical application is to provide coverage to a business or industrial park located close to a cable HFC plant, but separated by a physical barrier, such as a highway. As an alternative to running new fiber or coax, a wireless node can be interfaced to coaxial or fiber plant and used to create one side of a radio link between the node and the new coverage area. Wireless CPE in the area to be covered completes the link on the other side. The interface to the cable plant is via a cable modem within the interfacing node, which may be strand-mounted. BelAir Networks, for example, offers a strand-mounted wireless multiservice node that is plant-powered at 40 to 90 VAC and contains a DOCSIS 2.0-compliant cable modem. CPE on the other side of the wireless link is typically mounted on rooftops or at windows.
Wireless extensions are often configured with multiple nodes in a mesh topology to overcome the limitations of connectivity requiring line of sight between transmitter and receiver. Nodes in a mesh network can have two active radio links: an access link to end devices on the network and a backhaul link to other nodes. End devices will home on the node that provides the best signal path. Nodes will seek optimum signal paths via backhaul links to other nodes, forming a chain that eventually homes back to the landline-based HFC network. (See Figure 1, for model discussed by Christopher Skarica of Linsday Broadband in a SCTE Live Learning event.) Different radio technologies can be used to provide backhaul links and links to end devices. BelAir Networks, for example, offers the 100S two-way multiservice node that can be equipped with modules for 802.11 a/b/g Wi-Fi access links, an 802.11a pre-WIMAX backhaul link, and an 802.16d WiMAX radio module. Options are also available for 4.9 GHz public safety links. Operation can be in the 2.3 GHz, 2.5 GHz, and 4.9 GHz licensed bands, and 2.4 GHz and 5.25-5.85 GHz unlicensed bands.
But wireless extensions have a wider range of application than providing access across physical barriers. BelAir VP Marketing Dave Park pointed to an application that several cable operators were using in the hospitality industry. "Three cable companies are using wireless extensions to provide wireless data capability to the hospitality industry," he said. "In this application, multiple nodes mounted outside the hotel provide the link to guest wireless devices, alleviating the disruption of business required to extensively wire a building with internal hotspots." Cable companies have also used wireless extensions to provide data service on ferries and trains.
Data capacities of wireless extensions depend upon the radio technology and the topology of the mesh network, with a typical range being between 100 to more than 400 Mbps per square mile. A typical backhaul link can handle 25 Mbps, and the range for individual cells is 3-5 Mbps. Mobility applications Park said that the same technology used for wireless plant extensions provides wireless mobility. In this case, however, the point is not to bridge a barrier, but to overlay an existing HFC network with a wireless access method, such as Wi-Fi hot spots. In addition to being a source of new revenue, wireless mobility can also be used as a defense strategy or pre-emptive strike against overbuilders who pitch municipal wireless networks as an alternative to high-speed cable data. Working with Fujitsu and BelAir Networks, for example, Bresnan Communications has trialed a one-square mile wireless municipal network in Billings, MT.
The amount of protected revenue can be significant. In an actual conversion of a utility wireless network from a free to a pay-per-use business model discussed in these pages last October, it was found that 22 percent of 43,000 subscribers to the free network opted for continuing with the utility under the pay-per-use plan. Assuming comparable take rates for an overbuilt wireless access network, at $35 per month per subscriber for high-speed data service, that equates to $330,000 per month of lost business. FMC FMC is perhaps one of the most hyped but slowest to implementation applications of wireless technology in a cable system. The concept is based upon a dual-mode mobile telephone handset that can home to either a premises-based Wi-Fi connection or to a cellular service provider’s network, depending upon which source presents the strongest signal to the handset. While the subscriber is within the building where the Wi-Fi signal dominates, the connection to the other party is completed via the cable operator’s network, at a lower cost than for a cellular-based call. When the subscriber leaves the building, a seamless handoff to the cellular network occurs, providing a continuous call experience with complete mobility.
Kevin Neely, ARRIS director of product management for FMC, explained that FMC is implemented using his company’s mobility application server (MAS) with a session initiation protocol (SIP) client in the handset that is aware of both types of radios. "The MAS facilitates the handoff to the mobile network via a trunking gateway to a cellular partner’s mobile switching center," he said. "With a partnership arrangement, handoffs can occur in both directions for calls to other parties on either cellular or landline networks."
The need for a partnership with a cellular carrier may explain why FMC has been slow to arrive. Such arrangements have had trouble materializing.
Neely notes that in the interim before alliances between cable and cellular providers are formed, the MAS can be used to offer loosely-coupled FMC services such as a single reach directory number with simultaneous ringing of landline and mobile phones, and/or handoffs betweeLinn Wi-Fi connections and cellular providers, but only when the call has been originated by a landline phone. Strategic relevance As noted earlier, the companies that survive and dominate are those that take a broad view of their business. Cable began that process when it first offered data and telephony as services to complement a traditional strength in video distribution. The value of this foresight has been proven, as our customers’ view of communications moves toward multimedia and mobility.
Cable’s newest offerings, however, are the most vulnerable to new competition. Emerging wireless technologies such as WiMAX and LTE provide alternatives to cable’s data and telephony offerings, with the added dimension of mobility. Data revenue lost to a wireless overbuild, mentioned above, is only one competitive threat. Ignoring the communications needs of businesses that could be served via wireless extensions is another, where future service opportunities will also be lost if other providers satisfy communications needs now. Similarly, in FMC applications, it is equally possible for a cellular carrier to gain new revenue by extending its network into a residence or business (see sidebar above), as it is for a cable company to manage the call handoff process.
The bottom line is that although wireless may at first appear to be an offensive strategy for new business, the defensive dimensions of its use are just as relevant to cable’s future.
Justin J. Junkus is president of KnowledgeLink and telephony editor for Communications Technology. Reach him at [email protected].
