TD-CDMA, an acronym for Time-division

Time division multiple access

Time division multiple access is a channel access method for shared medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This...

 - CDMA

Code division multiple access

Code division multiple access is a channel access method used by various radio communication technologies. It should not be confused with the mobile phone standards called cdmaOne, CDMA2000 and WCDMA , which are often referred to as simply CDMA, and use CDMA as an underlying channel access...

, is a channel access method

Channel access method

In telecommunications and computer networks, a channel access method or multiple access method allows several terminals connected to the same multi-point transmission medium to transmit over it and to share its capacity...

 based on using spread spectrum

Spread spectrum

Spread-spectrum techniques are methods by which a signal generated in a particular bandwidth is deliberately spread in the frequency domain, resulting in a signal with a wider bandwidth...

 across multiple time slots. It is shown that a mixture of TDMA

Time division multiple access

Time division multiple access is a channel access method for shared medium networks. It allows several users to share the same frequency channel by dividing the signal into different time slots. The users transmit in rapid succession, one after the other, each using its own time slot. This...

 and CDMA provides better quality of service

Quality of service

The quality of service refers to several related aspects of telephony and computer networks that allow the transport of traffic with special requirements...

 for multimedia

Multimedia

Multimedia is media and content that uses a combination of different content forms. The term can be used as a noun or as an adjective describing a medium as having multiple content forms. The term is used in contrast to media which use only rudimentary computer display such as text-only, or...

 communication

Communication

Communication is the activity of conveying meaningful information. Communication requires a sender, a message, and an intended recipient, although the receiver need not be present or aware of the sender's intent to communicate at the time of communication; thus communication can occur across vast...

s in terms of data throughput

Throughput

In communication networks, such as Ethernet or packet radio, throughput or network throughput is the average rate of successful message delivery over a communication channel. This data may be delivered over a physical or logical link, or pass through a certain network node...

 and voice/video quality.

Standardized implementations

TD-CDMA is used in IMT-2000's 3G air interface, defined as IMT-TD Time-Division, and can also be found in use in UMTS air interfaces, as standardized by the 3GPP

3GPP

The 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...

 in UTRA-TDD HCR

UTRA-TDD HCR

UTRA-TDD HCR, an acronym for UMTS Terrestrial Radio Access-Time Division Duplex High Chip Rate, is a 3GPP standardized channel access method based on a combination of TDMA and CDMA ....

. UTRA-TDD HCR is closely related to W-CDMA (UMTS)

W-CDMA (UMTS)

W-CDMA , UMTS-FDD, UTRA-FDD, or IMT-2000 CDMA Direct Spread is an air interface standard found in 3G mobile telecommunications networks. It is the basis of Japan's NTT DoCoMo's FOMA service and the most-commonly used member of the UMTS family and sometimes used as a synonym for UMTS...

, and provides the same types of channels where possible. UMTS's HSDPA

High-Speed Downlink Packet Access

High-Speed Downlink Packet Access is an enhanced 3G mobile telephony communications protocol in the High-Speed Packet Access family, also dubbed 3.5G, 3G+ or turbo 3G, which allows networks based on Universal Mobile Telecommunications System to have higher data transfer speeds and capacity...

/HSUPA

High-Speed Uplink Packet Access

High-Speed Uplink Packet Access is a 3G mobile telephony protocol in the HSPA family with up-link speeds up to 5.76 Mbit/s. The name HSUPA was created by Nokia...

enhancements are also implemented under TD-CDMA.