Devices
A "Wireless Solutions Fast Start" Article

Wireless devices have evolved from several different starting points
· Cell phones
· Personal Digital Assistants (PDAs)
· Laptops
with a healthy dose of Consumer Electronics thrown in. Their evolutionary paths all lead towards the same point - converged devices that support voice, email, text messaging and web browsing - but their ancestry still shows in the final product.

Cell Phones 
Cell phones started as voice-only devices on analogue networks, and then a variety of digital networks appeared operating at different frequencies. If a cell phone can work on analogue as well as digital circuits, it is called dual-mode. If it can work on more than one frequency, it is called dual-band or tri-band. Because different countries use one of three frequencies, tri-band phones are often billed as world-phones. This is a bit misleading, as there are various network technologies (1XRTT, GPRS, I-mode) which are totally incompatible.

The digital networks provide web browsing, email, and SMS (Short Message Services, a.k.a. text messaging). Multimedia Message Services (MMS) is the big brother of SMS and allows multimedia such as voice, pictures and video, to be sent from one device to another over the carrier network, or by using email if interoperability between networks does not exist. Handsets can handle multimedia input or output, so expect to see capabilities such as cameras, voice recorders and video players.

Most cell phones do not support disconnected users or synchronization, except perhaps for phone lists. This is changing. 
Cell phones do not work on wireless LANS, which is a big limitation if you believe that public wireless LANs are going to become pervasive. 

Personal Digital Assistants (PDAs)
Wireless PDAs evolved from the desire to provide information access and computer programmability on a handheld device, under slogans like "computing power at your fingertips". Originally, wireless was not involved; neither was voice. The devices provided local copies of contact, calendar and task information, synchronized with copies on your desktop via a cable and cradle. Email was likewise handled in an off-line fashion. A copy of incoming mail could be stored on the handheld and read; new emails could be created, but would not be sent until your next synchronization. Mobility was achieved, but not immediacy.

With the introduction of wireless networks, and especially “always-on” connectivity, immediacy too was achieved. Email could be sent and received immediately over the wireless network. Web browsing too could be supported. There was no need for a desktop to be involved. Practically though, although modern PDAs allow pure wireless use, including synchronization, most systems retain synchronization between the mobile device and the desktop for moving large volumes of data quickly and cost effectively.

Wireless connectivity was achieved initially with bulky add-on jackets for the PDA, and later with internal antennae. Unlike the cell phone, wireless PDAs used either the carriers' voice-plus-data networks or wireless LANS, but not both (although this is changing with multi-network devices). The devices still looked like personal organizers, with a variety of competing bells and whistles. Screens became larger, brighter, and coloured. Numerous ways of entering data were developed.

Voice came later. Early wireless PDAs such as Blackberry used data-only networks such as ARDIS and Mobitex, which were in place years before the cellular carriers’ voice-plus-data networks, and before wireless LANS had the potential to provide a non-trivial market size. The way that voice is implemented depends on the type of wireless network being used. Devices using the carriers' voice-plus-data networks allow voice to be provided as well as data. Devices using wireless LAN connectivity use a technology called Voice Over IP (VoIP), which leverages internet technologies to provide voice. 

Convergence ... to What?
The evolution paths of the cell phone and the PDA both lead to the converged device, handling voice, web browsing, PIM, and synchronization. On the other hand, consumer devices have a definite fashion component. There is debate over whether consumers will end up using a single converged device (currently big and utilitarian), or whether they will have a utilitarian device for work, and a more fashionable device for evenings or hiking. One consideration is that phone numbers are not transferable across devices, so that you would need a separate phone number for each device. The carriers are not yet providing multi-device packages using the same phone number, but this might be a nice idea.

Current converged devices have inbuilt or slot0in support for multiple networks, and for good measure will support Bluetooth for personal area networking. This will be valuable in environments that have pervasive WLANs and pervasive carrier WANs, with valuable services on both.

Finally, the relationship between consumer electronics and wireless is still unfolding. There are now Network Camcorders that will allow you to email your picture directly to someone. And the whole concept of the Internet Appliance (including the infamous Internet Toaster) is still alive.

With all of these options, we can expect vigorous exploration and experimentation on the part of the device manufacturers, with results that will range from the must-have to the improbable. In a subsequent article, we will explore what this variety means for solutions providers.

 

Martin Stares is a respected speaker, author and coach in the field of wireless solutions and strategy for business, helping companies find innovative wireless solutions for their organizations. For more information and resources, visit Greyfriars Consulting Group at www.greyfriars.net. Read other articles in this series This article is one of a series call Wireless Solutions Fast Start, a course helping companies and individuals understand the business uses of wireless technologies. Visit www.greyfriars.net for other articles in this course. Free content for your web site Would you like to add this article and many others to your web site at no cost? The Greyfriars Wireless Solutions articles may be used on your site as long as the following conditions are met. The full content and links of each article must be used. The author and copyright notice must stay intact. The last paragraph describing the author and their business along with the link to their web site must be intact. If you do use one of our articles, drop us a line at enquiries@greyfriars.net so we can visit your site.