Each user is assigned a unique code to identify and separate calls sharing the same frequency at the same time. Users share one wide frequency band, using unique codes to identify and separate calls. GSM is the operating cellular system in many countries outside the United States where subscribers roam without borders. GSM offers the convenience of one phone number enabling users to be contacted wherever they may be traveling, providing GSM coverage is available. TDMA phones are idle between bursts, consuming less power than analog phones.
Subscribers can talk nearly twice as long without a battery change.
This method dramatically reduces the chances of call disruptions during handoff or of dropped calls due to a failed handoff. GSM operates on a different frequency than US cellular service and US cellular phone service will not operate overseas. PCS is a comprehensive communications service that offers services through micro-cellular technology. PCS features advanced applications such as custom call screening and call blocking. Some analysts believe that when fuly implemented, PCS may replace conventional wired telecommunications based on location to location dialing for voice and data transmissions.