METs need to consider the effects of mobile networks and telecommunication on the transitioning business.

	Mobile networks, together with mobile middleware and devices, provide support for a mobile platform
	that comprises the wireless Internet, smart clients, and mobile messaging architectures.
	Software vendors have made significant advances in providing reusable components and frameworks
	that sit on top of the mobile platform and facilitate rapid mobile application development.
	These applications make use of wireless networks, the mobile Internet, wireless application server
	frameworks, device emulators, WAP, and the corresponding development tools for mobile business solutions.
	Wireless Networks and Conversions

		Wireless networks are broadly grouped into short- and long-range networks. The Wi-Fi
		network standard is for WLAN.

		The IEEE 802.11b (Wi-Fi) system is also a popular wireless network, widely used in offices,
		homes, and public spaces such as airports, shopping malls, and restaurants.
		IEEE 802.11a and 802.11g are standards with much higher speeds, and they may replace
		Wi-Fi in the near future. Bluetooth technology, having limited coverage and throughput, is suitable for applications in Personal Area Networks (PANs).
		Cellular networks provide longer transmission distances and greater coverage, but they have
		a much lower bandwidth (less than 1 Mbps) compared with Wi-Fi standards.
		A recent trend in cellular systems is for “third generation” (3G) standards to support wireless
		multimedia and high-bandwidth services. Wireless networks are expressed as generations: 2G, 2.5G, and the recent 3G are well known.
		MET has to consider the transition from the current generation used by an enterprise to a new
		generation of networks. This transition includes not only switching to a new type of network but also the smooth transition of devices, applications, contents, and the use of middleware to achieve it.

Wireless (Mobile) Standards

		Wireless communication networks can be grouped under different standards. These standards
		form the backbone of mobile communications; but, they change at breathtaking speeds.
		Variations in standards and the phenomenal rate at which they occur are major impediments
		to the development of mobile applications and business solutions.
		In the context of MET, technology generations can be understood as spanning from the very
		first generation (G or 1G) through to the latest 4G and beyond. Initially, only voice communication was possible with 1G analog technology.
		With the use of 2G standards, the world turned toward digital technology for wireless
		communication, and in addition to voice communications, SMS was added.
		These gave rise to the demand for wireless Internet services, which were provided by the
		"second and a half generation" (2.5G) technology. Later, 3G evolved to provide fast Internet services live video and audio streaming, online games, and interactive multimedia.
		The data rate support of 3G is around 2 Mbps. Therefore, all these services cannot be
		available at the same time at the desired speed. This limitation is handled by the 4G standards that have ambitious goals, challenging research issues, and above all, never-ending user expectations.

	802.11 Standards:
	802.11 Standards were originally come into being in 1997 and registered in 1999.Its transfer rate is 1 or 2 Mbps. The specifications of 802.11 are three physical layers. 802.11 with direct-sequence spread spectrum was swiftly replaced and admired by 802.11b.The family of 802.11 Standards include many version to perform various functionality as following.

		802.11a
		802.11a same as original 802.11 Standards because it uses data link layer protocol and frame are same as used in 802.11 Standards. But the basic 802.11a. It uses 5 GHz bandwidth for operation and 54 Mbp/s data range. It is a very effective when you are performing more than one task at a time and or crowded time. The signals of 802.11a fascinated more willingly by walls. This happen may occur in all solid objects due to small wavelength.
		802.11b
		802.11b also uses the media defined by 802.11 standards It was come into view in 2000. 802.11b has the straight addition of modulation technology same as in 802.11. Mostly 802.11b suffered from the intrusion of other products. We need 2.4 GHz band to operate 802.11b. There are lots of devices operated by 2.4 GHz band in 802.11b such as Bluetooth, oven, card less phones, and monitors.

		802.11g
		802.11g was authorized in 2003 as a third modulation device with 2.4 GHz band. It provide maximum data rate with 54Mbit/s at physical layer. 802.11ga also used to for restricted purposes to forward error and improvement codes. The hardware of 802.11g is totally compatible with 802.11b. The most inspiring feature of 802.11g is speed therefore user adapting it rapidly. The manufacturing rate is also less as compared to others. The contribution of 802.11b will diminish the data rate on the whole 802.11g network.
		802.11n
		The amendments in 802.11 Standards are occurring with the passage of time and according to the requirement of user or network. The recent amendment in 802.11 Standards is 802.11n. It has multiple new features and MIMO but it also based on 802.11 standards. 802.11n recognized in 2009 as a final endorsement in 802.11 Standards family. All type of enterprises was previously transferred to 802.11n networks. These all enterprises based on Wi-Fi Alliance's.

	Wi-Fi is a certified product for 802.11n application to make 802.11 standard families more useful and
	compatible to new era because WiFi fulfill the requirements of new era where no need to spend time for the arrangement of wires or cables and so on. The 802.11 standard families amend a great deal in the form of WiFi network.

	Mobile Generations:
	Figure 9-5 shows the pictorial view of mobile generations

First Generation (1G; 1980s):
The first generation was based on analog systems, and it was deployed during the 1980s and it supported analog voice. The handsets were bulky, phones had poor voice quality, and there was no data transmission capability. In this generation, voice calls use Frequency modulation (FM) and frequency division multiple access (FDMA). Such systems typically use 25 MHz bandwidth for both forward and return links between the base station and handsets.

Second Generation (2G; 1990s):
The 2G networks use higher-order digital modulation techniques that support improved voice quality, network security, and call reliability. For efficient use of the frequency spectrum, 2G standards use multiple access schemes such as TDMA and CDMA. These are two cellular network standards for long-distance communication that are well-known and in use.
The first network standard is Global System for Mobile Communications GSM is a popular cellular standard for mobile phones developed in the 1980s. It uses the TDMA approach, in which frequencies are divided into time slots with each time slot allotted to phone calls. GSM allows compatibility and interoperability across geographical boundaries operating on the 0.9–1.8 GHz bands (1.9 GHz in the United States). Circuit-switched technology for data transmission enables SMS, which is very popular with GSM.

The second network standard is Code Division Multiple Access CDMA, which is based on a spread spectrum method, in which a signal is spread over a broad range of frequencies thereby reducing interference and increasing the number of simultaneous users within a frequency band. Each conversation is digitized and then tagged with a code in CDMA. In contrast to FDMA or TDMA where each user is allotted a particular frequency band or time slot, in CDMA the entire bandwidth is allocated for all users at all times. The use of CDMA technology has several advantages such as improved network capacity, immunity from interference by other signals, reliable connection, improved voice quality, network security, and optimum frequency reuse. For CDMA, a subscriber is attached to two adjacent cells simultaneously, ensuring smooth and seamless transition from one cell to another, which is transparent to the user.

2.5G (Late 1990s):
The standards of 2.5G are built on top of 2G standards and have backward compatibility. They support Internet applications with higher data rates, e-mails and Web browsing, and transactions and location-specific services. They have packet switched as well as circuit-switched implementations. Although 2.5G standards offer Internet services, their data throughput rates are not sufficient for high-speed broadband Internet and multimedia access. Also, these standards do not offer many services and are not flexible enough.
General Packet Radio Services (GPRS) is a packet-based data network on dedicated GSM channels.

However, it is not suitable for real-time Internet applications and Web browsing. GPRS networks can be shared by multiple users in contrast to HSCSD, thereby supporting a larger number of users. Transitioning businesses need to consider GPRS carefully, as their QoS might drop down rapidly as more users get connected.
IS-95B for 2.5G CDMA supports both packet- and circuit-switched data accesses. It is an upgraded version of IS-95 and represents 2.5G technology. IS-95B provides high data rates to individual users by combining multiple orthogonal (coded) user channels on a common CDMA radio channel.

Third Generation (3G; Early 2000s):
They provide capabilities for wide area wireless voice telephony, broadband networks that have high capacities and speeds, and global roaming. 3G applications include VoIP, audio and video streaming, faxing and e-mail, multimedia services on demand, and videoconferencing. These applications, however, when used by global mobile users require global standards to enable mobile interoperability.
UMTS Wideband-CDMA (W-CDMA), also known as Universal Mobile Telephone System (UMTS), provides continuous “always on” accessibility support for 3G networks. The high data rates of 2 Mbps per user enable multimedia applications, live audio and video streaming, and other high-speed Internet services.
CDMA2000 is an evolutionary 3G standard facilitating easier backward compatibility and a smoother transition path for users transitioning from earlier standards.

High-Speed Downlink Packet Access (HSDPA) is an upgraded path to W-CDMA. It provides 8–10 Mbps speed in the 5 MHz bandwidth using adaptive modulation and coding (AMC) techniques, multiple input multiple output (MIMO), hybrid automatic request, and improved cell search and receiver design. It is sometimes referred to as 3.5G technology as HSDPA is an intermediate packet based data service solution between the 3G and 4G technologies.

Third Generation (3G; Early 2000s):
They provide capabilities for wide area wireless voice telephony, broadband networks that have high capacities and speeds, and global roaming. 3G applications include VoIP, audio and video streaming, faxing and e-mail, multimedia services on demand, and videoconferencing. These applications, however, when used by global mobile users require global standards to enable mobile interoperability.
UMTS Wideband-CDMA (W-CDMA), also known as Universal Mobile Telephone System (UMTS), provides continuous “always on” accessibility support for 3G networks. The high data rates of 2 Mbps per user enable multimedia applications, live audio and video streaming, and other high-speed Internet services.
CDMA2000 is an evolutionary 3G standard facilitating easier backward compatibility and a smoother transition path for users transitioning from earlier standards. High-Speed Downlink Packet Access (HSDPA) is an upgraded path to W-CDMA.

It provides 8–10 Mbps speed in the 5 MHz bandwidth using adaptive modulation and coding (AMC) techniques, multiple input multiple output (MIMO), hybrid automatic request, and improved cell search and receiver design. It is sometimes referred to as 3.5G technology as HSDPA is an intermediate packet based data service solution between the 3G and 4G technologies.

Fourth Generation (4G; 2000s):
The 4G standards provide end-to-end IP solutions where voice, data, and multimedia streaming can function at higher data rates with the benefit of “anytime–anywhere” operations. Further, with high data rate throughputs of about 20 Mbps, which can be maintained for users moving at an average speed of 200 kmph, 4G networks operate in the 2–8 GHz bandwidth.
Applications in 4G include wireless broadband access, multimedia messaging services, video chats, mobile TV, high-definition TV content, and digital video broadcasting (DVB). Thus, 4G can be characterized as a fully IP-based integrated system that also converges wired and wireless technologies. According to the 4G working groups, infrastructure and terminals of 4G will encompass all standards from 2G to 4G, interfaces with legacy systems, and an open platform for extensions. Transitioning to 4G will require allocation, availability, standardization, and innovation decisions related to the network.

*Reference: Mobile Enterprise and Transition Management by Bhuvan Unhelkar.