Understanding Analong & Digital Phone Services
It doesn�t matter if you�re purchasing your first cellular phone, or upgrading to a newer model, you should still have an understanding of the basic technology involved and how it will affect the price you will pay for your phone and cellular service.
Analog Service
Analog is the oldest and most mature cellular service available. This means the costs to develop the calling network have already been recouped, and the price per calling minute will be relatively inexpensive. Additionally, analog networks have the widest area of coverage. The bad part of an analog cellular service is it can not take advantage of any of the new calling features like voice mail, caller ID, call forwarding, and internet access. Additionally the quality and clarity of calls is not as good as those of a digital service.
Digital Service
Digital cellular communications occur at two different bandwidths - 800 MHZ and 1900 MHZ. Within each bandwidth 4 completely different types of communications can exist, the first and oldest type being TDMA (Time Division Multiple Access). The next oldest type is CDMA (Code Division Multiple Access). While a CDMA cellular network is more expensive to develop, operate, and maintain, it is also more efficient than a CDMA network, allowing more calls to occur on a size of bandwidth. GSMC (Global System for Multiple Access) currently has very little use inside of the United States. It is being used mostly in Europe and Asia. ESMR (Enhanced Specialized Mobile Radio) isn�t really a cellular service. Instead it�s more like a walkie talkie service. While the communications are simplex (only one person can talk at a time) the range can be as large as nationwide. So if two people are on the same EMSR service they could talk from Maine to California without making a call. This is the communication network that Nextel uses. These devices almost always are combined with standard cellular capabilities as well.
Currently services on the 1900 MHZ band is not utilized as extensively, as that of the 800 MHZ band. However this is expected to change as the cellular networks continue to grow in the next few years. Cellular phones will come with two different designations dual, triple or quad band and single or dual mode. A single mode phone will be capable of using either analog or digital service only. A dual mode phone will look for a digital signal first and then use an analog signal when a digital one is unavailable. The more bands that a phone is capable of operating on, the more compatible it will be with a wider variety of cellular providers. The most common configuration for standard consumer phones is dual band / dual mode.
PCS is a sub grouping of digital communications. PCS (Personal Communication Service) consists of a bundled package of services. Exactly what services are offered will vary from one cellular provider to the next. Some common features being offered are caller ID, call forwarding, conference calling, voice mail, text messaging, Short Messaging System (SMS), Instant Messenger or chat services, Internet, and email access.