Understanding Digital CommunicationsUnderstanding Digital CommunicationsWhen purchasing a phone most consumers really aren't concerned about the differences of one digital network to another, they just want to be able to make and receive calls with a quality and clarity they can understand. The problem comes in when you try to compare phones from one digital network to another complexities are bound to introduce themselves making it hard for an apples to apples comparison of the service plans.

The digital cellular communication world known as Personal Communication System or PSC is made up of four major technologies:

CDMA - Code Division Multiple AccessTDMA - Time Division Multiple AccessGSM - Global System for Multiple communicationsESMR - Enhanced Specialized Mobil RadioTime Division Multiple Access or TDMA was the first digital cellular service made available. It works by taking the incoming signal slicing it into distinct time divisions or "slots" mixing it with other calls from other subscribers that occur for that same time division or slot and transmitting all of them together. This slicing and merging of different signals makes the network very efficient to use. Some advantages of TDMA are:

Efficient use of existing bandwidthProvides clear calls with high quality signalEfficient use of battery power for longer lifeEnhanced security and privacyAdditional features such as caller ID and text messagingCode Division Multiple Access or CDMA was the next service that became available to consumers. It was released in 1992 but didn't fall into common usage until 1995. CDMA is a much more complex system to implement and run than TDMA systems. This additional complexity means it is more costly to implement and maintain. In a CDMA network each call is not separated into channels but instead assigns a unique and individual signature to each signal allowing it to be taken apart and put back together in an efficient manner. Advantages of CDMA are:

Much more efficient use of existing bandwidth resulting in lower costs per communication time unitProvides clear calls with high quality signalsEfficient power and battery usageReduction in dropped calls compared to other servicesAdditional features such as caller ID and text messagingGlobal Systems for Mobile Communications or GSMC is used primarily by international cellular service providers, and has very limited implementation in the United States. GSMC technology is based on TDMA with some improvements. GSMC is divided up into smaller time divisions or "slots". However these slots can hold considerably more data making them more efficient. Another advantage of GSMC is the use of Subscriber Identity Modules or SIM cards. This allows information to be moved easily from on phone to another. Some advantages of GSMC are:

More efficient bandwidth utilization then TDMAExcellent call clarity and qualityEfficient use of battery compared to analog serviceEnhanced security and privacyAdditional features such as caller ID and text messagingTwo way data, voice, fax, and SMS communicationSubscriber Information Module (SIM) allows user to change phones and transfer information easily
  • Can be used around the world without configuration changes
    • Enhanced Specialized Mobile Radio or ESMR is similar to a digital radio type of communication. This allows connection between users on the same network to occur extremely quickly. This allows cellular phones to act as both as a cell phone and as a walkie talkie allowing fast, easy and secure communication. EMSR solutions are popular with courier services, large office, plant or manufacturing facilities offering the option of standard telephone or CB like communication. Advantages of ESMR are:

  • Push to talk walkie talkie feature
    • Group callingTwo way data transmissions

    Cell Phone Offers

    FREE

    YOU MAKE $50

    YOU MAKE $50

    $49.99
    FREE !!!