H/PCs and Wireless Communications

By Andrew Seybold

Today, accessing your desktop computer wirelessly is no simple matter, and convincing your IS department to provide wireless access back to your own corporate LAN can be even more difficult. However, there are a number of ways you can use wireless access and your H/PC to increase your productivity.

While version 1.0 of Windows CE requires the H/PC device to be connected to your desktop via a cable to synchronize the two, Windows CE Version 2.0 supports full remote synchronization. This is an important change. Now you can synchronize your H/PC data with data residing on your own desktop with a wired or wireless connection from wherever you are. I believe that this new feature will result in the development of wireless solutions for this class of product. This does not mean that wireless connections back to a user’s own desktop will instantly become easier, only that vendors will be addressing the problem with renewed interest.

In the meantime, there are a variety of services that provide wireless e-mail, Internet access, one-way and two-way paging and messaging, and fax send-and-receive capability. If you already have an Internet e-mail account, you can arrange to have it linked with a wireless network. Or you can have your e-mail forwarded to your wireless account. In some cases, by using a series of filters, you will be able to determine which messages will be forwarded and which will remain to be read later.

To become wirelessly enabled, you will need four things:

Most of the service providers offer a kit that includes a wireless modem, software to communicate with the network, and an account.

There are several different types of wireless networks that can provide service to H/PC users. If you have a cell phone and service, you can use a “cellular ready” analog PC Card modem to connect to your Internet Service Provider. Slip the modem in the H/PC, connect it to your cell phone via cable (make sure you get the right cable), and dial up as though you were using a wired phone. The caveat here is that dial-up cellular works best at 9.6 Kbps or slower, rather than the 28.8 or 33.6 Kbps you might be able to achieve with wired phones. You are charged for airtime just as though you were making a voice call, and extra seconds are usually rounded up to the next whole minute.

The U.S. has a number of different digital cellular standards. If you are in an area where the PCS GSM system is offered, you will be able to connect your H/PC to it via a PC Card cellular modem adapter, which consists of a PC Card and a cable. You insert the card in your H/PC, connect the card to your GSM phone via the cable, and dial up at 9.6 Kb. This system requires an additional phone number for the same phone (one for voice, one for data). Once enabled for data, the phone can be connected to the H/PC and used much like a regular dial-up modem. The GSM data system is digital, thus it is far more robust than analog cellular. Users will not experience circuit drops or speed and throughput degradations that are often experienced with dial-up cellular.

Packet-Data Network Modems

All of the packet-based wireless systems offer some level of security. ARDIS and RAM’s security is inherent in the design of the network. Messages sent via these systems are broken up and sent in discrete “packets” of data. The packets from one message are intermingled with packets from other communications. In addition, these networks may operate on multiple frequencies, depending upon where a user is. This mingling of message packets and multiple frequencies mixes things up enough to make intercepting individual messages relatively difficult. Although not foolproof, these systems are sufficiently secure that users should not have to worry about their privacy. For those who do, the CDPD (cellular digital packet data) networks currently deployed an added level of security in the form of data encryption. There are also “end-to-end” encryption programs available that encrypt a message before it is sent and decrypt it after it is received.

Most wireless modems are Type II PC Cards with an extension on the end of the card that houses a battery, transmission and reception circuitry, and the antenna. The modems presently on the market use a 9-volt battery to power the transceiver. Depending upon the type of device the modem is used with — desktop, notebook, H/PC, etc.— users can set the system to recharge a 9-volt NiCd battery or use a throwaway alkaline battery.

One advantage to using wireless modems is that they are self-powered. They do not draw power from the H/PC and do not require an external source of power to operate for long periods of time. If you have used an external PC Card modem with your H/PC, or even the 14.4-Kbps modem built into the Philips Velo, you know that without external power, card modems dramatically reduce your H/PC’s battery life.

Each wireless network requires a modem specifically designed for that network. Motorola makes the Personal Messenger Wireless Modem Card for use with the CDPD and ARDIS networks, while Research In Motion makes one for the RAM Mobile Data network. (This wireless modem is also OEM’d by Megahertz and sold as its AllPoints Wireless PC Card.) There are other wireless modem vendors, but their products are designed for use in notebook or laptop computers as opposed to H/PCs. Most of these require a Type III PC Card slot (two Type II slots stacked) and draw all of their power from the computer.

Wireless Networks vs. Service Providers

You can obtain wireless service directly from wireless network providers—ARDIS, CDPD, RAM, SkyTel, or Metricom. You can also access it from one of a number of service bureaus that specialize in various wireless data services. The best known of these are RadioMail (ARDIS, CDPD, RAM, and dial-up), Wynd Communications (RAM), DTS/Zap-it (RAM), Locus (RAM), and Infowave (RAM and CDPD).

Each offers basic e-mail and wireless access as well as ancillary services. Fax send and receive, text-to-speech, and other services are available depending upon your requirements. Service costs also vary, but a typical, heavy e-mail user will find that his or her monthly wireless data bill will run in the $40-$75 per month range. Several of these companies offer tiered, flat rate pricing, so the more you use the service, the cheaper it is per kilobyte.

All of these service providers offer Internet e-mail access. If you want to surf or browse the Net, Go America offers software that will enable text-based access to the Net. (Graphics over wireless is a less than pleasing experience because of the slower data speeds.) In many cases, your existing Internet provider can work with one of these services to provide an extension of your ISP e-mail address over a wireless network so that a separate mailbox will not be required. (For example, aseybold@outlook.com is auto-forwarded to aseybold@radiomail.net.) The only caveat here is that attachments generally cannot be sent over a packet-data network, and some systems limit the size of the files that can be sent and received. In my case, I limit the size of a wireless file to about 2K and hold the larger messages on my server.

New Types of Services

Most of the companies mentioned above have released or are about to release upgrades to their systems that will help provide access back to a user’s own e-mail and information resources. There are still many issues to deal with to be able to connect directly back to a desktop computer on the corporate side of an Internet firewall. However, Wynd, RadioMail, DTS, Infowave, and Locus all offer corporate solutions that will permit a corporate LAN to be securely connected to one or more wireless data networks. Several other companies are also working on solutions and Microsoft is working with the Portable Computer and Communications Association to find ways to provide secure, inexpensive links between corporate LANs and wireless data networks.

The H/PCs

Here at Outlook, we perform compatibility tests of wireless devices and mobile computing devices. Computers generate radio frequency signals that can affect the performance of the radio modem, and radio modems can interfere with a computer’s CPU, memory, and/or display.

The good news is that all of the H/PCs we have received for testing have passed with flying colors. It appears that H/PC vendors have taken the time and effort to make sure that their H/PCs are RF-friendly. So far, we have tested the NEC, Casio, Compaq, and Hewlett-Packard devices. (The Velo we received from Philips did not include the optional PC Card slot. However, we were able to determine that the Velo does not emit any RF that would interfere with a wireless modem, and also that an RF modem in close proximity does not cause interference to the Velo.) We have not been able to test the Lucky GoldStar (LG) or Hitachi units (they are the same). However, since LG is offering a unit with a CDPD modem, our assumption is that these units are RF-friendly as well.

H/PCs and RF Modems

I have been using several H/PCs with wireless modems for several months. I have experimented with RadioMail, Wynd, and DTS. All of the devices and services work well. I have grown accustomed to running my life via wireless e-mail and it has become an important part of my mobile arsenal. Anyone needing quick and easy access to their e-mail during the course of a day when they are mobile will quickly come to appreciate the convenience of wireless access from an H/PC.

All of the wireless e-mail software I am using installs under the H/PC Inbox, and changing from dial-up to wireless is as easy as tapping on the “service” item in the menu bar of the Inbox and choosing which network or service you want to use under “connect.” Now that Windows CE version 2.0 supports remote synchronization, the next step will be for these service providers to extend the reach of their products to include not only e-mail access but calendar and file synchronization as well. Some interesting work is being done in this area, both in terms of corporate and individual solutions. Several companies are working with software that will be installed on your desktop system to “push” your e-mail and synchronization information out to a private web site (beyond the firewall). You will not have to pass through your corporate firewall, and all of the wireless networks are connected to the Internet.

Windows CE version 2.0 makes it possible to provide users with remote synchronization and will, I believe, drive the adoption rate of wireless H/PC access. Today it is possible to use wireless connectivity to be more productive, it is cost effective, and, while not easy, it can be implemented. It is only going to get better. Now that Microsoft is interested in wireless as an enabler to Windows CE communications look for better and faster solutions.

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