0G refers to pre-cellular mobile telephony technology. These mobile telephones were usually mounted in cars or trucks. Typically, the transceiver (transmitter-receiver) is mounted in the vehicle trunk and attached to the "head" (dial, display, and handset) mounted near the driver seat

16ary Quadrature Amplitude Modulation (16-QAM), one of the forms of QAM, is a modulation scheme. In QAM, the constellation points are usually arranged in a square grid with equal vertical and horizontal spacing, although other configurations are possible. Since in digital telecommunications the data is usually binary, the number of points in the grid is usually a power of 2 (2,4,8...). Since QAM is usually square, the most common forms of QAM are 16-QAM, 64-QAM, 128-QAM and 256-QAM. By moving to a higher-order constellation, it is possible to transmit more bits per symbol. However, if the mean energy of the constellation is to remain the same (by way of making a fair comparison), the points must be closer together and are thus more susceptible to noise and other corruption; this results in a higher bit-error rate and so higher-order QAM can deliver more data less reliably than lower-order QAM.

First Generation wireless technology (1G) is the original analog, voice-only cellular telephone standard, developed in the 1980s. One such standard is NMT (Nordic Mobile Telephone), used in Nordic countries, Eastern Europe and Russia. Others include AMPS (Advanced Mobile Phone System) used in the United States, TACS (Total Access Communications System) in the United Kingdom, JTAGS in Japan, C-Netz in West Germany, Radiocom 2000 in France, and RTMI in Italy. Analog cellular service is being phased out in most places worldwide.

1xEV-DO, also known as Evolution Data Optimized (EV-DO), is a third-generation (3G) cellular data technology for GPRS-enabled cellular phones, networks and handheld devices. Its bandwidth is up to 3.1Mbps.

1xEV-DV, also known as Evolution Data/Voice (EV-DV), is a third-generation (3G) cellular data technology for GPRS-enabled cellular phones, networks and handheld devices. Its bandwidth is up to 3.1Mbps.

1xRTT is a cellular data technology for CDMA networks. RTT stands for Radio Transmission Technology. 1xRTT has a theoretical maximum of 144 Kbps of bandwidth, but achieves a practical throughput of only 50 to 70 Kbps in the real world.

2.5G refers to the bridging technologies between second (2G) and third generation (3G) wireless communications. It is a digital communication allowing e-mail and simple Web browsing, in addition to voice. The key technologies include GPRS and WiDEN.

2G stands for the second generation of mobile wireless communication technology, which uses the digital technologies for the mobile communication. 2G technologies can be divided into TDMA-based (GSM) and CDMA-based standards depending on the type of multiplexing used. It allows slow data communications, but its primary focus is voice.

The 3.5G generally refers to the technologies beyond the well defined 3G wireless/mobile technologies. Currently, HSDPA (High Speed Downlink Packet Access) is considered the primary 3.5G technology which is a software upgrade of WCDMA and provides high-speed broadband wireless access.

3G stands for the third generation of wireless communication technologies, which support broadband voice, data and multi-media communications over wireless networks. Main 3G standards include CDMA2000, WCDMA, UMTS, etc.