The Goal of 4G

4G must be clearly more than 3G in terms of services, applications, and technology. As a comparison, 4G is not a combination of High Speed Uplink/Downlink Packet Access (HSUPA/HSDPA) or Wireless LAN (WLAN).

3G networks are inadequate to accommodate WLANs as access networks, which offer data rates of 11 Mbps. The goal of 4G will be to replace the entire core of cellular networks with a single worldwide cellular network completely standardized based on the IP for video, Voice over IP (VoIP) and multimedia services. The newly standardized networks would provide uniform video, voice, and data services to the cellular handset or handheld Internet appliance, based entirely on IP. As 4G standards are not defined so there is plenty of room for other applications to overlap into the 4G space.

The 4G providers of advanced cellular technology are adopting Concatenated Coding which has the capability of providing multiple Quality of Service (QoS) levels. forward error correction (FEC) coding adds redundancy to a transmitted coded signal through encoding prior to transmission. A major advantage of Concatenated Coding over the Convolution Coding method will be an improved network performance by the combining of two or more coding techniques, such as a Reed-Solomon and a Convolution Code into one Concatenated Code. The combination improves error correction combining with error detection. FEC using Concatenated Coding allows a wireless network to send much larger blocks of data while reducing bit-error rate, thereby increasing the overall through-put.

The primary goal of the planned 4G cellular services will include: Interactive Multimedia, Voice, Video Streaming, High Speed Global Internet Access. Virtual Private Network (VPN) Availability, Service Portability with Scalable Mobile Services, High Speed, High Capacity, Low Cost Services, Improved Information Security, QoS Enhancements, Multi-Hop Networking.

Table 1 compares here various Wireless Communication Technologies.

Table 1: Comparison of wireless communication technologies 

	1G	2G	2.5G	3G	4G
Transmission	Analog	Digital	Digital	Digital	Digital
Architecture		Circuit Switch	Packed-Switch	Circuit and Packet Switch	Packet Switch
Speeds		9.6 to 14.4 Kbits/s	64 to 144 Kbits/s	384 Kbits/s to 2 Mbits/s	100 Mbits/s to 1000 Mbits/s
Standards	AMPS	TDMA, CDMA, GSM	GPRS, EDGE, 1×RTT	WCDMA, CDMA-2000	Single unified standard
Service	Mobile telephony (voice)	Digital voice, short messaging	Higher capacity, packetized data	Integrated high quality audio, video and data	Dynamic information access, wearable devices
Multiplexing	FDMA	TDMA, CDMA	TDMA, CDMA	CDMA	CDMA
Core Network	PSTN	PSTN	PSTN and Packet network	Packet network	Internet
Handoff	Horizontal	Horizontal	Horizontal	Horizontal	Horizontal and Vertical

4G MOBILE COMMUNICATION SYSTEMS

The success of Second-generation (2G) mobile systems in the previous decade prompted the development of third-generation (3G) mobile systems. While 2G systems such as GSM, IS-95, and cdmaOne were designed to carry speech and low-bit-rate data, 3G systems were designed to provide higher data-rate services. During the evolution from 2G to 3G, a range of wireless systems, including General Packet Radio Services (GPRS). International Mobile Telecommunications-2000 (IMT-2000). Bluetooth, WLAN, and HiperLAN, have been developed. All these systems were designed independently, targeting different service types, data rates, and users. As these systems have their own merits and demerits, there is no single system that is good enough to replace all the other technologies. Researchers are making efforts to establish 4G systems that integrate existing and newly developed wireless systems as a more feasible option. Different research programs, such as Mobile Virtual Centre of Excellence (VCE), MIRAI, and DoCoMo, have their own visions for 4G features and implementations.

At present, plethora of wireless technologies with their own merits and demerits exist globally; the upcoming 4G mobile communications system is foreseeing potentially a smooth merger of these technologies with a goal to support cost effective seamless communication at high data rate supported with global roaming and user customized personal services.

As discussed 4G will be an IP based wireless network replacing the old Signaling System 7 (SS7) telecommunications protocol, which is considered massively redundant as shown in figure 1 This is because SS7 signal transmission consumes a larger part of network bandwidth even when there is no signalling traffic for the simple reason that it uses a call setup mechanism to reserve bandwidth, rather time/frequency slots in the radio waves. IP networks, on the other hand, are connectionless and use the slots only when they have data to send. Hence there is optimum usage of the available bandwidth.

Figure 1: Example of IP based networks

 

The goal of 4G will be to replace the entire core of cellular networks with a single worldwide cellular network completely standardized based on the (Internet Protocol) IP for video, packet data utilizing Voice over IP (VoIP) and multimedia services. The newly standardized networks would provide uniform video, voice, and data services to the cellular handset or handheld Internet appliance, based entirely on IP (Internet Protocol).