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WIRELESS COMMUNICATIONS ON YOUR HP PALMTOP
It's getting so easy to send and receive e-mail on your Palmtop you no longer need to be close to a phone!
By David ShierI had just used my cellular phone to call for a tow truck when my Skytel 2-way pager started to buzz. Tom Rundel and I were returning to Southern California from a PDA developer's conference in San Mateo (Northern California). My car had been overheating on the way up to the conference and finally broke down. Two friends in a separate car (Dave Marsh and Richard Nelson from EduCALC) had left after us. They were aware of the overheating and Dave used his Skytel 2-Way pager and HP 200LX to send a message to see how we were doing.
I sent a reply telling them that we were stuck in Salinas and waiting for a tow to the Ford dealer. An hour later, I had just finished signing the paper work when I heard a familiar voice call out my name. I turned around to see Dave and Richard. Fortunately, the car only took an hour or two to fix, but if it had been more serious, Dave and Richard would have given us a ride home.
That's the way wireless messaging is supposed to work. Unfortunately, the reality for many people is that they never get a chance to enjoy such events because the current wireless market seems to be a confusing collection of "buzzwords" and options. How can you possibly select a system for yourself without getting a graduate degree in wireless technology?
Since I found myself in the same situation, I will attempt to sort all this out for you in this article. I've included a glossary of wireless terms, but you shouldn't need them all in order to select the system that's right for you.
Types of wireless systems
While there are dozens of wireless communications options available for your Palmtop, we can easily separate them into five categories: One-way pagers, two-way pagers, cellular-compatible modems, digital cellular systems, and finally radio modems.
Within these five major categories, you will find numerous vendors, each offering unique services and pricing options. However, by first choosing which of the five basic categories is right for you, it will be much easier to make a decision among the vendors in that category.
By far, the simplest of the wireless devices are alpha-numeric pagers, which come in models that can be connected to the Palmtop via the serial port or as PC Cards. Pagers that can connect to the Palmtop all support receiving text messages. These messages can be sent using software you install on an office PC,via e-mail or by calling the service provider and dictating the message to an operator.
Hewlett Packard's Starlink card is an example of this type of device. Pagers are inexpensive to purchase (or lease) and the monthly service charges are typically as low as $20 for local service and less than $100 for national service complete with news, sports and stock portfolio messaging.
Pagers have other advantages. They are simple to operate and most (with the exception of the Starlink card) can display messages without being connected to the Palmtop. Pagers are currently the one practical wireless tool for always getting immediate notification that someone has sent you a message. They are on all the time, and alert you when a message comes in. Because of their size and battery life, it is very easy to carry them with you all the time. Because of this, even if you use another wireless device, you may still want to use a pager to receive notification that you have a new message.
One of the most interesting features of the HP Starlink pager is its ability to receive from your office updates to your Palmtop's Appointment Book. This makes the Starlink worth considering for sales and service representatives that often get schedule changes dictated from the home office.
Of course, pagers have one major disadvantage: they can only receive messages. If you want to reply or originate your own messages, then you will need to use something else.
If you like the features of a pager, but would also like to reply, then the two-way pager could be right for you. Currently, the only national two-way pager service is offered by Skytel using the Motorola Tango Pager unit. You can purchase a Skytel/Palmtop Connectivity Kit from Skytel that comes with a special cable to connect the pager to the Palmtop. The kit also includes System-Manager compliant communications software, and a case to hold the Palmtop, pager, cable and a few small accessories -- all for less than $50.00.
The pager can receive alpha-numeric messages of up to 512 characters. There are 16 short replies built into the pager which you can send without connecting to the Palmtop. They include messages such as YES/OK, NO, TRAFFIC DELAY, NEED MORE INFO, etc.. Personally, I think they could have done a better job of selecting the messages: many are redundant and there isn't a THANK YOU reply in the bunch. So if you want to respond to that helpful message which is getting you out of a jam with a friendly "thanks," you will have to connect the pager to the Palmtop and write your reply there.
When connected to the Palmtop, you can generate replies of up to 95 characters. Your pager has an Internet address, which is the pager's PIN number with @skytel.com added to the end. This lets anyone on the Internet send you e-mail messages. You can then write a reply to that message and send it wirelessly. Unfortunately, Skytel does not provide a means of entering an arbitrary Internet address, so you can't generate an e-mail message to anyone that hasn't sent you a message first. Also, the return path for replying to messages sent to you are only kept by the Skytel system for a few weeks. After that, you can't send a reply.
Still, even with these limitations, the two-way pager has proven very useful. Even when you don't connect it to the Palmtop, the Tango has features that a normal pager can't duplicate. Most importantly, the Tango sends an acknowledgement when a page is received. If the Skytel network doesn't receive a confirming "answer-back' from your unit, it will resend the page. This allows someone sending you a page to know that it was received.
One way I use the Tango is to verify that our company's e-mail server is operating properly. We set up a separate e-mail address which automatically forwards messages to my pager. That means that every time a message is received in this address, it is automatically forwarded to my pager. If I want to check to see if the server is running, I use my pager to send a message to this address. If everything is working, the message is forward back to my pager, confirming that the system is operating.
Using a conventional modem with a cellular phone seems like a simple solution to wireless communications. All you should have to do is connect your Palmtop to the phone via the modem and use your communications program to log onto your online service. The problem with this approach is that cellular phones don't always provide a continuous signal.
The cellular phone network is divided into "cells." Each cell has one or more transmitter/receiver that handles the calls in a certain geographical area. When you move out of one area and into another, a computer that monitors this switches you to the cell of the area you are moving into. The problem is that sometimes there is a momentary loss of signal and this can cause the modem to drop the connection.
Standard modems are not designed to tolerate a signal loss. Some cellular phone users have successfully connected to online services using their Palmtop, cell phone and standard modem, provided they are stationary.
Cellular-ready modems are designed to tolerate momentary signal loss, but even with these modems, data connections are tenuous at best. Also, unlike other wireless communications methods, when using a cellular phone, you pay by the minute for the connection time. All other wireless systems either charge by the amount of data being transferred, or in some cases provide unlimited usage for a fixed monthly fee. Also, if you move outside of the area serviced by your cellular provider, you will need to pay a roaming charge (around $5/day) plus the charges for the calls themselves.
Still, if you already have a cellular phone and a modem for your Palmtop, and you only need wireless communications occasionally, then this might be a cost effective alternative.
One nice feature of using a cellular connection is that you can use the same software and e-mail system that you use with conventional phone lines. This avoids the need for two or more e-mail addresses, which is necessary with the pagers and radio modems (with the exception of the Ricochet modem discussed below.)
Digital cellular systems: The HP OmniGo 700LX
The 700LX is basically an HP 200LX with a built-in PC card modem and a docking cradle on the top for a Nokia digital cellular phone. The 700LX provides faxing and e-mail using a feature of GSM digital cellular service known as Short Messaging Service or SMS. This service, and therefore the 700LX itself, is currently available only in Europe and parts of Asia and the Pacific Rim. Because the U.S.A. is currently fighting over competing digital cellular technologies, we don't expect to see the 700LX released here for quite some time.
The HP 700LX has been discussed in previous Palmtop Paper articles, so I won't go into a lot of detail here (see November/December 95 issue, page 29). However, I will briefly compare the 700LX to the other wireless technologies. The SMS service provides much of the same features of the radio modems, plus the advantage of cellular voice service. According the Gilles Kohl, incoming SMS messages are first stored on the Nokia phone, and then transferred, on the push of a button, to the Palmtop. This allows you to receive messages even when the Palmtop is off. The number of messages that your phone can store is limited, but only if you don't retrieve them using the Palmtop.
On the Palmtop, messages are stored in a database. You can also export to file (making archiving of old messages easy). As soon as you retrieve SMS to the Palmtop, they get deleted in the phone, making room for more incoming messages.
A nice feature of the OmniGo 700LX is the ability to automatically dial a phone number selected from the Palmtop's PhoneBook application. Since GSM and SMS services are not currently available in the USA, it's difficult to compare the cost of using the 700LX to the radio modem services available from Ardis and RAM Mobile Data. There are a few cities in the nation where GSM service is becoming available, specifically Washington, DC and San Diego, California. However, unless your mobile messaging needs are confined within your local area, the radio modem services appear to be your only viable alternative for the foreseeable future.
I really don't care for the term "radio modem." To me, this seems to imply a modem that you can use the same way you use a regular modem, but only wirelessly. With the exception of the Ricochet modem (discussed below), this is not the case. Radio modems communicate only with their own special services. There are two major radio networks in the USA: Ardis and RAM Mobile Data. While these two systems are not compatible with each other, they are very similar in function. Both allow you to communicate from one radio modem to another. Also, both offer optional services that provide you an Internet address and news stock quotes or even access to text from World Wide Web sites. These added services are from RadioMail or WyndMail.
Radio modems are available as external units (affectionately known as "bricks") or as PC Cards from Motorola and MegaHertz.
The Motorola Personal Messenger 100D is used with the Ardis network, while the MegaHertz AllPoints Modem works with RAM Mobile Data. The two network shave slightly different coverage areas, so it's a good idea to check the service availability in the areas you most often visit.
A great advantage of these radio modems is their ease of use. There's no logging in, roaming, no access numbers, simply plug the modem into the Palmtop and run the RadioMail software. If you are within range of the network -- regardless of where you are in the country -- your e-mail will be sent to you automatically and you can send your own. No other system is easier. If you are out of the service area, or if the modem is off, the network will save your messages and send them to you when you turn the modem back on. Thus, you never lose your e-mail.
A new feature of the RadioMail service is a text-based Web server. By sending the Web page address (known as the URL) to the RadioWeb e-mail address, you will get an e-mail message in return that contains the text from the Web Page. Of course, you only see plain text without any of the graphics, and the speed and cost prohibit this method from being practical for "web surfing" (moving aimlessly from link to link) but it is very useful for retrieving specific information wirelessly.
THE RICOCHET SYSTEM
A new player in the wireless business is the Ricochet modem. This is an external modem that can wirelessly communicate using standard software. This is a distinct difference from the other radio modems, which require proprietary software to run. Instead, the Ricochet modem accepts standard "AT" commands that make it look like a normal modem to the Palmtop and the software.
The Ricochet modem gets its name from the way the wireless network is set up: Your modem communicates to a transmitter/receiver mounted on a near-by street light pole. This unit then relays your communications to the next pole-mounted unit, until it finds its way to one connected to the wired network. This has the advantage that the pole-mounted units don't need any expensive wiring in order to bounce your signal to the next one. The disadvantage is that the Ricochet system needs lots of these pole-mounted units -- one every half mile or so. This means that the Ricochet is not practical for rural areas.
Still, the Ricochet is fast (up to 28.8Kbps, but more typically about 9600bps) and can be used with software that the others can't. For example, I simply configured our acCIS program to dial the special CompuServe access number provided by Ricochet, and specified COM Port 1, then I was able to wirelessly connect to CompuServe and collect my e-mail and send out replies.
Another unique feature of the Ricochet modem is that there are no connect-time charges! For a flat monthly fee you get the modem and unlimited access to the Internet.
Unfortunately, with its NiMH rechargeable battery and cable, the Ricochet modem is heavy, plus the cabling needed to connect it to the Palmtop is unwieldy. Of course, if you're a regular reader of the Palmtop Paper, it won't surprise you to know that my company (SHIER Systems) is now making cable to directly connect the Ricochet modems to the HP Palmtop.
The only other disappointment is the coverage area for Ricochet. Currently, they have "wired" a number of university campuses around the USA, and most of the San Francisco Bay area. Seattle Washington is scheduled for late 1996 and Washington, DC in 1997.
However, for those lucky enough to be within Ricochet's coverage area, its system and the Palmtop can be a very liberating combination. A case in point is Ms. Anne Mitchell, an attorney in Palo Alto, California who runs Father's Rights and Equity Exchange (F.R.E.E.), a national father's rights advocacy group.
According to Mitchell, "The portability and versatility of the 200LX with the Ricochet wireless modem has really freed me from being chained to the desk and computer." Because the vast majority of the work Mitchell does takes place in e-mail communications with others all around the country, often requiring nearly instant response, she said "I had days where I was in front of my computer for, quite literally, 16 hours straight. Now I can go wherever I want, and always have immediate access to my e-mail."
Mitchell's enthusiasm for her HP 200LX and Ricochet modem is clearly evident, as she told me "I can finally leave the office for an afternoon, and even go out to lunch! I affectionately refer to the local Starbucks as "my branch office."
The ideal solution
With all these competing technologies, the question remains "Which is the best?" The answer greatly depends on your needs and location. Personally, I feel a combination of a conventional alpha-numeric pager -- to provide an immediate alert of an incoming message, and a radio modem -- to read the full text and write replies or faxes, is the most usable at this point in time.
What I'd like to see in the future is a unit the size of the Tango two-way pager (or even smaller) with the features of the Ricochet modem -- especially the unlimited Internet access for a flat fee. Such a unit could replace my pager, modem and radio modem, and could clip to my belt. Of course it would need coverage in most locations around the country and even around the world -- perhaps using satellite communications. I hope that such a device is not too many years away. However, now that I've had a taste of what wireless communications can offer today, I would never consider waiting for something new. While each type of technology has its limitations, they all provide means of staying in touch and being productive, whenever and wherever the need arises -- and after all, isn't that why we have these wonderful Palmtops in the first place?
Copyright © 2010 Thaddeus Computing Inc