BDMA (Beam Division Multiple Access): The BDMA method separates the antenna beam as per the locations of the mobile stations. An orthogonal beam is allotted to each mobile station during the communication between base stations and mobile stations. This increases the capacity of the system by allowing the mobile stations to give numerous accesses. Mobile stations and the base station know each other‟s positions precisely, being in a Line of Sight (LOS). Hence they can transmit beams that point to each other‟s position to communicate with no interference with the mobile stations at the cell edge.
Bluetooth: Bluetooth is an unlicensed consumer device that is used for very short-range wireless personal area networks (WPANs). Bluetooth uses 2.4 GHz spread spectrum frequency hopping technology, and is included in devices such as mobile, radio, telephones, laptops, personal computers, printers, and personal digital assistants (PDAs). Some experts are predicting that it will become a regular feature in many consumer electronic devices.
DECT: DECT technology is created for short-range use as an access mechanism to the main networks. The applications provided by DECT are cordless voice, fax, data and multimedia communications, wireless local area networks, and wireless PBX.80 The advantage of this technology is that it provides good voice quality and very high radio link reliability.
DECT is generally operated in the 1880-1900 MHz frequency range in Europe. This frequency is unlicensed and exclusive to DECT devices, which secures operation with almost no interference. Outside of Europe, frequencies ranging from 1900 MHz to 1920 MHz and 1910 MHz to 1930 MHz are also widespread. These ranges are also unlicensed but not solely for DECT use. Nevertheless interference is not a big concern in these frequencies either, as they are generally adequately free of other users.82 About 60% of the cordless communication world market is controlled by this technology.83 In India, the 1880 – 1900 MHz or the 1910 -1920 MHz ranges need to be de-licensed to operate DECT devices.
Fixed Mobile Convergence: Fixed Mobile Convergence (FMC) is one of the latest technological developments utilizing Wi-Fi technology. FMC uses the public IP network to spread all or part of the services offered by the wireless telecom service provider‟s core network (CN) to domestic, small and medium enterprise subscribers. Some of the benefits of FMC are:
- There is greater technological practicality, because users only have one contact number, as well as use the same device for fixed and mobile services
- Indoor coverage is enhanced, because the wireless signal is disseminated from within the indoor environment
- There is a reduction in the bandwidth load, because voice and data traffic are offloaded from the wireless to the fixed portion of the network
- The expenses incurred by the service providers as well as subscribers are reduced
A viable option for delivering FMC is through Unlicensed Mobile Access (UMA). The UMA standard combines wireless cellular telephony and Wi-Fi networking for voice, data, and multimedia services available on one dual-mode handset (DMH). This method of communication allows the use of a single device indoors and outdoors without a loss in quality, and even a potential improvement. The DMH device can automatically alternate between an IP-based network and a cellular network; the network choice being dependant on where the strongest signal is coming from. UMA promises a solution for converging fixed wire services, mobile wire services, and VoIP services.
Frequency Hopping: This is a modulation technique that is employed in the spread spectrum signal transmission. It involves the continuous switching of frequencies in the process of radio transmission. This reduces the chances of interception or jamming of signals.
Near Field Communication (NFC): NFC is a radio technology that operates at a short range using the 13.56 MHz frequency. Communication between two NFC-compatible devices is activated when they are put within the proximity of about 4 cm. NFC can be applied to mobile handsets, enabling them to interact with posters, magazines, and various products. NFC applications also include electronic wallets which would act like credit cards through the handset.
OFDMA (Orthogonal Frequency Division Multiple Access): Orthogonal Frequency Division Multiplexing (OFDM) is a method for transmitting a bulk quantity of digital data over spectrum. The advantage of this technique is that it reduces the amount of crosstalk within signal transmission. This is done by dividing the radio signal into several sub-signals and transmitting them to the receiver at the same time using different frequencies.88 OFDMA provides for a multiple access on the same channel. It distributes subcarriers between all users so that everyone can transmit and receive simultaneously.
RFID: Radio Frequency Identification (RFID) is used as a reference to a system that uses radio waves to wirelessly transmit the identity of an object or person in the form of a unique serial number. RFID applications include ID tags, EZPasses, SpeedPasses, and many others.
Software Defined Radio (SDR): This is a compilation of hardware and software technologies where some or all of the radio‟s operating functions use modifiable software or firmware that operate on programmable processing technologies. SDR enables new wireless features and applications to be included in existing radio systems without the need for new hardware.93 The potential for implementing SDR devices for spectrum sharing is through programming the technology to sense available spectrum in the vicinity of the device and coordinate with other communication endpoints to avoid interference.
Spread Spectrum: This transmission method modulates a signal over multiple carrier frequencies at the same time.95 As a consequence, the energy for transmitting the signal is spread over a wider bandwidth, appearing as noise.96 Transmissions using spread spectrum are more secure, interference is reduced, and the bandwidth-sharing is enhanced.
Ultra Wide Band (UWB): UWB is a wireless technology that transmits large quantities of digital data over wide frequency channels at a short distance using very low power. It is mainly used for voice and data transmission utilizing digital pulses and radar applications.
ZigBee: ZigBee is an open global standard of wireless technology which is used for low-cost, low-power machine to machine (M2M) networks. This standard uses unlicensed bands in the ranges of 2.4 GHz, 900 MHz and 868 MHz. ZigBee has the advantage of enabling the operation for years on inexpensive batteries for a variety of monitoring and control functions. ZigBee has standards for energy management, home and commercial automation, health care, retail, telecom, and consumer electronics. It is used for a multitude of purposes, such as smart energy/smart grid, AMR (Automatic Meter Reading), lighting controls, building automation systems, tank monitoring, HVAC control, medical devices and fleet applications.About 40% of the 2010 IEEE 802.15.4 chipset shipments were composed of ZigBee products. It is estimated that this number will grow to almost 55% in 2016.