Exciting changes are coming to pervasive wireless data communications. Just imagine accessing information, anytime, anywhere. How about real-time corporate data and e-mail? Enhanced communication everywhere?
But which wireless network to adopt? Given the extensive array of options, diversity of applications and variance in pricing and throughput, the right decision is a very personal one. There are very few cookie-cutter models in the wireless world today.
Let's consider the four main options available on today's wireless data landscape:
2. Packet Data
3. Cellular Data
For delivering the broadest array of coverage for low volumes of data at a relatively low cost, it is hard to beat the paging networks. The networks are pervasive and available from an array of carriers. Paging comes in three flavors:
One-way: The least expensive of the paging alternatives, one-way offers the best coverage and is one of the easiest solutions to deploy. However, it is only viable for pushing information to users, providing no way of verifying whether or not the message was received.
Two-way: With two ways paging truly interactive applications can be developed to facilitate effective two-way interactions. The carriers that offer two-way paging are more limited than those offering one-way and one and a half-way.
One and a half-way paging has most of the same limitations as one-way paging, with the notable exception of being able to acknowledge the receipt of a message within a full-coverage area. Two-way is considerably more expensive than one-way paging.
Another difference between the various paging options is coverage. While paging provides the best coverage of all wireless data options, there is a substantial difference between one-way and two-way networks. Both have basically the same coverage in receive mode, but once a user responds to a message the user must be in a full coverage area, which is a substantially smaller network footprint than the one-way paging network. All devices utilizing the two-way paging network are automatically switched between basic and full coverage, and the user is notified when their coverage area switches.
In addition to the low cost, another key differentiator between paging and various wireless choices is in-building coverage. The in-building coverage of the paging networks set the standard by which all other wireless data networks are compared.
Paging network carriers offer a range of pagers, and a variety of paging add-ons are being offered for handheld computers like the PalmPilot, Handspring Visor and a variety of Windows CE devices. Also emerging are paging capabilities built-in to some of these handheld computers.
While the paging networks are useful for sending small amounts of information, they are not 100 percent reliable for mission-critical applications and were not designed for data transfer.
Two relative newcomers to the packet data space, Cellular Digital Packet Data (CDPD) and Metricom's Ricochet network, were designed to offer the advantages of packet without its speed and cost drawbacks. Although American Mobile Ardis and BellSouth Wireless Data operate at raw data speeds of up to 19.2Kbps, these networks seldom achieved this level of throughput, operating in the 4.8K to 8Kbps range in most real-world applications. CDPD is rated at 19.2Kbps data throughput, and although it seldom reaches that speed, CDPD provides a more viable solution for applications that require better performance than BellSouth Wireless or Ardis networks. CDPD is slightly less expensive than these other solutions, however, it doesn't provide coverage in as many areas as Ardis and BellSouth Wireless.
Metricom's Ricochet network is in a category all its own. From a coverage standpoint it is currently only available in three cities: the Greater San Francisco Bay Area, Seattle and Washington D.C. However, thanks in large part to an equity investment of $600 million by MCI and Paul Allen's Vulcan Ventures, Metricom plans to rollout the network in 12 markets with an average data speed of 128Kbps by this summer. With data speeds of 128Kbps, Ricochet is years ahead of its competition in delivering high-speed, always-connected wireless data access.
The advantages of packet data over paging or circuit-switched data are the intrinsic error detection and correction capabilities these networks were designed to handle. Additionally, the connection is virtually instantaneous, as opposed to the dial-up delays common to circuit-switched networks. For the public sector (police, fire, etc.), real-time access to small amounts of mission critical information has proved to be a central component to their infrastructure. In the transportation industry and for field sales and customer support personnel, these networks have been a godsend. Organizations are willing to pay the premium pricing these networks carry because of the productivity and execution gains realized.
While cellular data networks were built for voice, the migration toward cellular data networks is progressing at a staggering pace. Sprint's rollout of its nationwide wireless data network based on CDMA in September 1999 marked the beginning of a revolution that will bring the Internet to hundreds of millions of mobile phone users in only a couple of years.
Cellular data networks have several advantages over paging and packet data networks. First they can effectively carry both voice and data on a single device. Sprint has done an excellent job in rolling out their Wireless Web service and has aggressively marketed their services. Bell Atlantic and others rolled out their wireless data networks shortly after the launch of the Sprint data network, and new announcements are being made almost weekly.
From a pricing standpoint, wireless data access using the cellular data networks is expensive when compared to voice. However, when comparing the cost of cellular data networks with most packet data network, cellular is substantially less expensive. For a megabyte of data sent over the Sprint network for example, the cost would be approximately $20, whereas the cost would be several hundred dollars for the paging networks BellSouth Wireless and American Mobile Ardis.
The primary cellular data network in the United states is CDMA, and that is not expected to change for quite some time. CDMA delivers a consistent throughput speed of 14.4Kbps, but, unlike packet data networks, it requires the user to initiate the connection that causes a slight delay and does not deliver an always-connected solution.
Very few wireless applications will justify the cost and limitations inherent in satellite systems. Using Iridium (which filed for Chapter 11) as an example, the wireless airtime is tremendously expensive, the network requires very large equipment with very limited in-building coverage and the data transfer speeds are very slow. In fact, the only real advantage of using satellite networks for wireless data communications is for very remote areas that cannot be covered by any other network.
A range of devices, consisting mostly of paging devices, PDAs with integrated wireless data capabilities and add-on cards for existing devices are currently available. RIM has released a line of products that includes the Inter@ctive 850, 950 and Blackberry pager, designed primarily as e-mail access devices. Motorola has developed a line of two-way pagers and cards that add paging capabilities and the like to the Palm Pilot and other handheld devices.
Integrated wireless data communications will be the catalyst that will lead to the pervasive use of handheld computers. The Palm VII is the first successful mainstream implementation of integrated wireless, but many similar devices are in development. Companies such as Handspring, with its Springboard expansion slot, are providing an easy way to add wireless capabilities to the existing devices.
In the future, many companies will integrate a technology called Bluetooth to enable a PDA or other mobile device to communicate with each other through a radio frequency (RF) link that will be built into mobile phones, PDAs, notebooks and desktop computers. In this scenario, the mobile phone would be the most likely device to facilitate this wide area network solution.
Other devices include PCMCIA cards that install into notebook computers to instantly add wireless data capabilities. A variety of cards are offered including solutions for both analog and digital cell phones, as well as PC cards based on CDPD or Mobitex (BellSouth).
WAP (Wireless Application Protocol)
WAP, as defined by the WAP Forum, is an open, global specification that empowers mobile users with wireless devices to easily access and interact with information and services instantly. Via WAP, mobile phone users are able to easily access Internet content and services. According to Dataquest, by 2003 the worldwide mobile phone market will reach 1 billion subscribers, and, according to IGI Consulting, the WAP-enabled mobile phone market will reach 330 million new users. This is consistent with the current state of the handset market, whereby 36 percent of all new mobile handsets feature a WAP browser.
The first implementations of WAP have been from the wireless phone carriers. AT&T was the first with its PocketNet offering. However, due to the limited choices of handsets available, the limited base of content and applications and AT&T's decision to limit the content users could access from the Internet, PocketNet has seen very limited success in the marketplace. AT&T has relaunched the PocketNet service with a new line of handsets and enhanced content offerings.
Sprint recognized the execution and marketing issues that plagued AT&T with its PocketNet service and launched a much more compelling product and content offering supported by a wide range of content partners. Additionally, it recognized the major mistake that AT&T had made by creating a closed system that did not allow users to access other Internet sites.
If carriers try to discourage users from accessing content beyond what the carrier provides, the adoption of wireless data services as a whole will be stifled. As carriers begin to understand the unique aspects of WAP and understand that, like the Internet itself, closed systems do not work and pervasive open systems benefit most players involved.
By the end of 2000, hundreds, perhaps thousands of unique WAP content sites will begin to appear, offering a variety of content and services ranging from e-mail to personalized content to e-commerce-related applications optimized for small screen mobile phones.