Will your field workers still need to communicate with each other via voice:

a) internally within your organization or

b) externally to customers, suppliers or business partners?

If so, how often?

Once you have determined the need for voice, determine whether:

c) one-to-one   communications or

d) one-to-many communications is desired.

For example, in public safety, it may be necessary for field officers to talk as a group, so that everyone is informed of a given situation. (one-to-many)  In a Taxi or Courier applications, voice may be required occasionally, but only on a one-to-one basis, to speak directly with the dispatcher. In the service industry, such as with Cable TV installation for example, both one-to-one internal voice communications to the dispatcher and one-to-one external communications to customers may be necessary.

In some types of business, group communications can create teamwork or enhance safety, yet in others it can create idle chatter. Which of these situations applies in your business?

Once you have determined the type's of communications that are optimum,  make a determination whether this communications should be:

e) dispatch push-to-talk oriented voice or

f) full duplex telephone voice.

Generally, for internal communications, push-to-talk communications tends to be more convenient and more efficient than standard cellular full duplex telephone service. Imagine an incident where police are staking out a robbery and having to phone each other to coordinate efforts! Or the situation where a taxi driver just needs some directions from the dispatcher. Dispatch communications is much more effective in these types of situations. On the other hand, cellular telephone (full duplex) communications can be advantageous for communicating externally to clients, as push-to-talk dispatch may confuse them.

Keep in mind that voice requirements will drop substantially for internal communications, once data dispatch is employed.

For each class of field people in your company, fill out a simple matrix such as this one to summarize your voice requirements:

Total Voice Requirements

Devices utilizing a web browser for data dispatching tends to be more cost effective from an airtime pricing standpoint than devices with a separate wireless modem.  Cellular type handsets with web browsers also can carry the benefit of having integrated voice communications. (all-in-one) Finally, they tend to be carrier subsidized, making them attractive from a capital cost standpoint.

However, other important factors must come into consideration, such as durability, required peripherals, out of range operation, local processing requirements, (running other programs on the device) and so on...

However, having chosen the device and the voice requirements, it's time to determine what your alternatives are for available networks that meet your needs. This is relatively simple, at least at first pass. Check out the websites for the cellular packet data carriers in your area and compare their coverage.

Make a note of the most appropriate choices for later reference. Before a final decision is made, you will likely want to do some active field testing with those chosen carriers and a couple of your field workers.

Remember, judging a carrier purely on their specification for data speed is akin to judging an automobile on horsepower alone. There are many other factors that come into play on performance. Secondly, most dispatch or AVL (Automatic Vehicle Location) applications are not that data intensive and you would not likely notice the difference between 20kbps and 100kbps.

Suffice it to say then, that iDEN, GPRS and 1X networks are likely on equal footing in respect of data speed and capacity, at least in terms of most dispatch applications.

What is more important to determine is which network package best satisfies your needs, given your chosen devices and anticipated usage . Talk to your software and hardware suppliers about the anticipated data capacity required and any price / performance trade-offs or decisions that must be made.

If the selected device is a carrier offered product, look for the subsidized hardware pricing, which is often based on the length of the airtime contract.