Ten years ago, there was a great deal of skepticism about wireless delivery systems for fast and efficient multimedia applications. But as the technology improves, with a flurry of activity by many companies including Philips NV, GEE Macron Ltd and Hewlett Packard Co, many in the industry are in bullish mood, particularly about the possibilities […]
Ten years ago, there was a great deal of skepticism about wireless delivery systems for fast and efficient multimedia applications. But as the technology improves, with a flurry of activity by many companies including Philips NV, GEE Macron Ltd and Hewlett Packard Co, many in the industry are in bullish mood, particularly about the possibilities of high speed multimedia access to the internet. Analog telephone transmission speeds are inadequate for video, graphics and high-fidelity sound so the race is on to find cost-effective, fast delivery systems. While Cable and satellite delivery systems are clearly in the running, many believe that radio delivery has added benefits. Wireless cable company AT (American Telecasting Inc.) is offering high-speed internet access. The company has approximately 145,000 video customers in 30 markets and is pursuing small to mid-sized businesses that want local area network-based internet access. With our low infrastructure costs and an ability to get to small penetration levels early, wireless cable is ideally situated to get in front of cable and the high-speed marketplace, says Robert Hostetler, president and chief executive officer of AT.
By Fiona Keating
MMDS (Multichannel Multipoint Distribution System) operators will have to compete against cable providers when they launch video services. But as Matthew Oristano, chairman of People’s Choice TV, a wireless cable company suggests, the set-up costs can be much lower. MMDS opponents are quick to point out the limited penetration capabilities of a single MMDS data channel. But MMDS companies are targeting slow access problems by researching the area of greater bandwidth efficiency. Of particular interest is the use of sectored antennae as a means of achieving reuse of the radio spectrum. Because of the overlap of beams, sectorization is of limited use as a means of expanding the user base among household customers. A specific business can be easily targeted, however, with a frequency within a single sectored beam. Another business can be provided with dedicated services over the same frequency from a separate beam. Antenna manufacturers are working on developing more advanced beam targeting capabilities such as active array, where frequency reuse can be applied across the full market base, greatly increasing the number of potential customers per data channel.
MMDS operators also have the option of dividing their markets into cells, similar to the way mobile phone areas are broken down, thereby lowering the number of potential customers per transmitter. This is currently being tested by CAI Wireless Systems. Some operators note that digital compression allows an increase in the number of TV channels on offer. Over the average MMDS system, adding eight channels leaves 25 6MHz channels for video, or enough to provide for approximately 100 digital television services. It is also thought that freeing up more spectrum for data is the simplest solution to increasing the customer base. CAI Wireless Systems Inc claims it can send data at speeds of 27 Mbps over its wireless Internet service, much faster than connections such as ISDN. However, wireless delivery systems have their critics, who claim that the drawbacks include higher prices, regardless of what the MMDS companies may say, as well as less reliability than existing services. Many users complain that wireless systems have been hampered by ‘dropped calls’. Those supporting radio delivery applications have come back strongly. Telecommunications company Ameritech has its own wireless broadband service for voice, video and data communications. They claim that the technology is quicker and cheaper to install than fiber. Using 38GHz microwave technology, Ameritech will be able to provide local access service for its customers as well as network diversity and back-up recovery. The service is aimed at businesses already using T1 or T3 lines, and Ameritech say that the cost is comparable. LMDS (Local Multipoint Distribution System) frequencies can be used as an interactive service overlaid on top of digital broadcast MMDS. This could lead to improved video on demand services and interactive TV. Some believe these multimedia applications can become commonplace within four to five years. One of the attractions of LMDS as a two-way link to the user is that unlike some other delivery mechanisms it offers sufficient bandwidth to accommodate both TV and data services. Another advantage is the possibility of setting up built-in transmitter/receiver antennas for devices such as laptop PCs and portable TV sets. It’s believed in many quarters that LMDS could be an alternative to coaxial cable for last-mile distribution of broadband services. Where MMDS is broadcast from a single transmitter at a distance of 30 miles in all directions, LMDS is designed to operate from smaller cells, with each transmitter covering a radius of about five miles, depending on the technology used and local atmospheric conditions. Antennas for MMDS are approximately two square feet in size, whereas LMDS antennas are about six square inches and can operate in a two-way mode much more easily than MMDS. Although it’s possible to achieve high levels of interactivity and near video on demand with MMDS, many believe LMDS is the better option for full interactivity. Philips Broadband Networks say that their system is complementary to cable. Transmitters are installed extremely quickly, with systems up and running in about two days. It’s also a highly adaptable system and effective in mountainous regions as in Switzerland, where cable is used up to a certain point, and then wireless systems take over in more inaccessible areas. Radio can also be used in places where environmental issues are important.
As wireless is a line-of-site-system, problems in reception may be caused by buildings which give rise to shadowed areas. However, these issues which can be corrected by using microcells and small transmitters. In Hong Kong, radio transmitters are placed on the top of buildings and cables are fitted down the sides, rather than laying cables on the floor. R&D of wireless delivery systems to produce killer applications such as multimedia on the internet seems to be growing stronger. It has received much attention from leading companies wanting to provide their user base with more viable options and there is a growing call from users for fast, cost-effective access. To meet the demand, US company Thomson Consumer Electronics is producing 700,000 digital wireless set-top boxes per year. We’re going to be able to reach more customers with digital,’ says Dick Alston, president of the Wireless Cable Association International Inc. As we market wireless cable aggressively and consumers become aware of it, they’re going to find it’s better value. It’s going to be lower priced and give them the programming they want.
This article originally appeared in Multimedia Futures.