Search results
Results from the WOW.Com Content Network
The top five wireless providers operate nationwide wireless networks which cover most of the population in the United States, while smaller carriers provide native network coverage across selected regions of the United States while supplementing nationwide coverage through roaming agreements with other carriers.
Mobile virtual network operators (MVNOs) in the United States lease wireless telephone and data service from the four major cellular carriers in the country—AT&T Mobility, Boost Mobile, T-Mobile US, and Verizon—and offer various levels of free and/or paid talk, text and data services to their customers.
In 3G, the most prevalent technology was UMTS with CDMA-2000 in close contention. All radio access technologies have to solve the same problems: to divide the finite RF spectrum among multiple users as efficiently as possible. GSM uses TDMA and FDMA for user and cell separation. UMTS, IS-95 and CDMA-2000 use CDMA. WiMAX and LTE use OFDM.
Multi-carrier code-division multiple access (MC-CDMA) is a multiple access scheme used in OFDM-based telecommunication systems, allowing the system to support multiple users at the same time over same frequency band. MC-CDMA spreads each user symbol in the frequency domain.
The Universal Mobile Telecommunications System (UMTS) is a 3G mobile cellular system for networks based on the GSM standard. [1] Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the International Telecommunication Union IMT-2000 standard set and compares with the CDMA2000 standard set for networks based on the competing cdmaOne technology.
Exclusive use for M2M, emergency communication and Smart Metering. Alliander Netherlands: CDMA2000 1xRTT, EV-DO Rev. A 450 May 2016: 3 MHz [5] [6] Private network for critical infrastructure. Exclusive use for M2M communication and Smart Metering. 450connect Germany: CDMA2000 1xRTT, EV-DO Rev. A 450 Nov 2016: 2x 1,25 MHz [7] [8] [9] [10]
List of countries by number of telephone lines in use; List of countries by smartphone penetration; List of multiple-system operators; List of telecommunications companies. List of telecommunications companies in the Americas; List of telecommunications companies in Asia and Oceania; List of telecommunications companies in Europe
With the evolution of CDMA to CDMA2000 and 1xRTT, the use of IS-95 CDMA Circuit Switched Data declined in favour of the faster data transmission speeds available with the newer technologies. Prior to CSD, data transmission over mobile phone systems was done by using a modem, either built into the phone or attached to it.