Search results
Results from the WOW.Com Content Network
UMTS, IS-95 and CDMA-2000 use CDMA. WiMAX and LTE use OFDM. Time-division multiple access (TDMA) provides multiuser access by chopping up the channel into sequential time slices. Each user of the channel takes turns to transmit and receive signals. In reality, only one person is actually using the channel at a specific moment.
Hughes Software Systems, Multi Carrier Code Division Multiple Access, March 2002. German Aerospace Center, Institute of Communications and Navigation, History of Multi-Carrier Code Division Multiple Access (MC-CDMA) and Multi-Carrier Spread Spectrum Workshop, November 2006. Wireless Communication Reference Web Site, section about MC-CDMA, 2001.
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]
This predates and is distinct from its use in mobile phones. The Qualcomm standard IS-95, marketed as cdmaOne. The Qualcomm standard IS-2000, known as CDMA2000, is used by several mobile phone companies, including the Globalstar network. [nb 1] The UMTS 3G mobile phone standard, which uses W-CDMA. [nb 2]
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.
Technologies like AMPS, TDMA, iDEN and CDMA 1x/EV-DO were used in the past by some of those networks and have been phased out in favor of newer systems. On 20 April 2022, Oi’s mobile network operations were sold to the country's three largest carriers, Vivo, Claro and TIM. [36]
In Russia and some other countries, local carriers received licenses for 450 MHz frequency to provide CDMA mobile coverage area. Many GSM phones support three bands (900/1,800/1,900 MHz or 850/1,800/1,900 MHz) or four bands (850/900/1,800/1,900 MHz), and are usually referred to as tri-band and quad-band phones, or world phones ; with such a ...
Initially almost one third of US population was in the channel 51 exclusion zones. As of August 2016 T-Mobile US has cleared almost all exclusion zones by either subsidizing relocation of channel 51 stations or by obtaining a permission to use 700 A block while the stations still operate on channel 51. [11]