Road Map and Challenges in 4G Wireless System

& ical Elect c tr r e Journal of Rathore et al., J Elec Electron 2012, 1:3 on urna l of E l ic Systems DOI: 10.4172/2167-101X.1000104 Electrical & Electronic Systems Jo ISSN: 2332-0796 Research Article Research Article OpenAccess Open Access Road Map and Challenges in 4G Wireless System A. K. Rathore*, R. K. Chaurasia, R. Mishra and H. Kumar Department of Electrical and Computer Engineering, National University of Singapore, Singapore Abstract The user demand for high speed multi-media application has been increasing many folds in the recent years. New smart phones are launching in the market. The wireless communication is looking forward for a new generation technology that will match the application demand and resources. This is where the fourth generation (4G) wireless communication is required. 4G wireless communication is expected to provide better speed, high capacity, low cost IP based services. The main objective of the 4G wireless communication is to supersede the current core technology with a single unified technology. More and more advanced interactive multimedia applications are emerging as 4G networks resulting in a rapid development of video coding and communication techniques. This paper deals with the current scenario and the future prospects of the 4G system in addition with the challenges it is going to witness. Keywords: Broadband wireless access; Content delivery; Sub- of the mobile devices, available bandwidth and transmission efficiency carrier; Multimedia services of the wireless network, universal access capability of the infrastructure, and the compression and error control efficiency of video and graphics Introduction data. Mobile phones are moving faster to provide the user the same or even better experience than the personal computer, but there is 4G or Fourth generation is the future technology for mobile long way ahead. From a mobile communication point of view, it is and wireless communications. Approximately 4G deployments are expected to have a higher data transmission rate as comparable to expected to be around the year 2010 to 2015. It will be the successor wire line network. Also the expectation is over service and support of 3G network technology. Voice is the basic drive force for the for seamless connectivity and access to any application regardless of second generation (2G) mobile communication [1], whereas video device and location. The expectation of mobile communication is the and television services are the chief factor for 3G. In the case of 4G key feature of 4G. It is going to describe the next complete evolution in low cost and high speed data are the dominant driver. High degree of wireless communication. It is also expected to provide a comprehensive personalization, application ubiquity and synchronization between user IP solution where multimedia services can be delivered to the user appliances are also the driven forces. The evolution to 4G from 3G will on an ‘anywhere anytime’ basis with a satisfactory data rate and high be driven by the services that offer better quality in multimedia, voice security. The current 3G wireless infrastructure is not able to achieve and sound. Personalization will be improved with greater bandwidth this demand. The International Telecommunication Union (ITU) is and sophistication in large quantity of information. Convergence with working on the standard and targets for the commercial deployment other network service will come through high session data rate. The of 4G system in the year 2010-2015 timeframe. ITU defined IMT- impact on the network capacity is expected to be significant. advanced as the successor of IMT-2000 or 3G [3,4]. Video communication is facing many challenges now. 4G wireless The advantage of 4G over 3G is listed in table 1 below. It is networks will provide many features to handle this [2]. It will provide obvious that 4G has much more system improvement over 3G. This the end-users more opportunities and flexibilities in accessing video and improvement is not only in bandwidth and capacity, but it also appears multimedia contents. It accommodates radio access systems via flexible in coverage, latency, mobility and security. core IP network, resulting in a very high data rate, and enhancing the video applications. It provides better quality of service and security Status & Key Technologies supports to the end users, and enhances the user experiences and In order to discuss the multimedia communications across 4G privacy for multimedia applications. The quest for video applications networks, it is obvious to unfold the key technologies and innovations and services would bring in a large volume of data transmission onto in 4G. The 4G system will include all the standards that the earlier the wireless network. This is going to be a potential challenge for the generations have been using. The figure 1 shows the evolution in the 4G systems. technologies from 1G, 2G, and 3G to 4G in wireless systems. 4G also Now a day it is quite interesting to note that the new mobile phones, contain the wireless local area network system to broadband wireless specially the smart phones, are not just the simple phone but much more than that. They are a little mobile PC and functions more or less like that. They includes a keyboard rendered on a touch screen, provide *Corresponding author: Akshay K Rathore, Department of Electrical and user friendly graphical user interfaces, provide internet services, web Computer Engineering, National University of Singapore, Singapore, E-mail: browsing, email connecting, local wireless fidelity connectivity, built [email protected] in camera, high quality music player capability, and small media Received June 17, 2012; Accepted July 18, 2012; Published July 21, 2012 management besides phone call functionalities. Citation: Rathore AK, Chaurasia RK, Mishra R, Kumar H (2012) Road Map and However there are many features that some smart mobile do not Challenges in 4G Wireless System. J Elec Electron 1:104. doi:10.4172/2167- 101X.1000104 support yet. This includes mobile television support to receive live programmes, multi user networked three- dimension games, realistic Copyright: © 2012 Rathore AK, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits 3D scene rendering and high definition visuals. The lack of these unrestricted use, distribution, and reproduction in any medium, provided the functions are due to computational capabilities and power constraints original author and source are credited. J Elec Electron ISSN: 2167-101X JECEC an open access journal Volume 1 • Issue 3 • 1000104 Citation: Rathore AK, Chaurasia RK, Mishra R, Kumar H (2012) Road Map and Challenges in 4G Wireless System. J Elec Electron 1:104. doi:10.4172/2167-101X.1000104 Page 2 of 4 3G 4G Generation Partnership Project) as the major step for Universal Mobile Architecture WAN W-LAN & WAN Telecommunication System (UMTS) [8]. Its function is to provide Information type Voice is prime, data secondary Converged data and an enhanced user experience for broadband wireless networks. It multimedia services supports a bandwidth ranging from 1.25 MHz to 20 MHz. It supports Data rate 384 kbps – 2 Mbps 100 Mbps (moving), both frequency division duplex and time division duplex. The peak 1Gbps (standing) downlink rate is 100 Mbps and peak uplink rate is 50 Mbps in a 20 MHz Frequency 18 – 2.4 GHz 2 -8 GHz channel. Its high speed is achievable because of great improvement in Class of switching Both circuit and packet Only packet the spectral efficiency. It has a low latency of the order of 100 ms for and Multiple access technology CDMA OFDMA 5 ms for control-plane and user-plane respectively. LTE also supports a Broadcast Not supported Supported seamless connection to all the existing networks such as GSM, CDMA Quality of service Less supported Supported and HSPA. LTE also provides IP based traffic as well as quality of service Table 1: Comparison of 3G and 4G wireless system. for the multimedia services. LTE uses a multiple input multiple output (MIMO) system in order Mobility to achieve high throughput and spectral efficiency. It uses 2×2 (two transmit antennae at the base station and two receive antennae at the High 4G terminal side), 3×2 or 4×2 configuration for downlink [9]. In addition, LTE supports multimedia broadcast multicast services (MBMS) either Pre in single cell or multi-cell mode. Most carrier supporting the GSM or 4G HSPA networks have upgraded their system to LTE. Carriers using 3G different standards are also upgrading their system to LTE. Middle Pre UMTS terrestrial radio access evolving from LTE has two different 3G air-interface technologies. Here the downlink is based on OFDMA and 2G the uplink is based on SC-FDMA. Wi Low 1G MAX Conventional OFDM is widely a key technology for the downlink W- LAN transmission scheme for E- UTRA frequency division duplex and time 1980 1990 2000 2005 2010 2015 division duplex modes [10]. Here the available spectrum is divided into multiple sub-carriers, and each sub-carrier is modulated independently Figure 1: Evolving of technologies and their mobility. by a low rate data stream as compared to OFDM. This orthogonal OFDM allows for the multiple users to access the available bandwidth. It access. 3GPP LTE/ LTE – advanced, 3GPP2 UMB and Mobile WiMAX assigns specific time-frequency resource to each individual. According based on IEEE 802.16m are the technologies that are widely adopted for to scheduling here the data channels are shared by multiple users. The the deployment of 4G [5]. complexity of OFDMA is increased but this result in efficiency and One of the unique features of 4G networks is that they will latency. accommodate heterogeneous radio access systems, which will be OFDMA signal has weaker peak to average power, therefore it connected via flexible core networks. Thus, an individual user can results in worse uplink coverage. So the uplink transmission is based on be connected via a variety of different access systems to the desired Single Carrier FDMA. The signal processing for both these technologies networks and services. The interworking between these different access are same, hence the parameterization of downlink and uplink can be systems in terms of horizontal and vertical handover and seamless harmonized. Here DFT- spread- OFDM has been selected for E-UTRA, service provision with service negotiation including mobility, security where a size M DFT is applied to a block of M modulation symbols, and quality of service management will be a key requirement. It may and then DFT transforms the modulation symbols into the frequency be handled in the core network or by suitable servers accessed via the domain [5]. The resultant signal is then mapped onto the available sub- core network. This optimally connected anywhere, anytime view could carriers. DFT processing is the fundamental difference between SC- be realized by a network comprising a variety of interworking access FDMA and OFDMA signal generation. Each subcarrier of an OFDMA systems connected to a common packet-based core network. signal only carries information related to a specific modulation scheme, whereas SC-FDMA contains all the transmitted modulation symbols IMT-Advanced has been developed to provide true end-to-end IP because of the spread process. services to mobile users at anytime and anywhere basis. Although the standardization process is still ongoing, the major design goals of 4G The main advantages of Orthogonal Frequency Division are quite certain. It includes that 4G will be all IP networks. This means Multiplexing (OFDM) is that it supports a high data rate by dividing that circuit switching will be eliminated in the next-generation cellular an entire channel into many overlapping narrow-band sub-channels by networks. Another point is that 4G will have a very high data rate. It is using orthogonal signals [11]. Different subcarriers can be allocated to expected that 4G networks will be capable of providing 100 Mbps data different users in order to provide a flexible multiuser access scheme and rate under high mobility, which is much faster than 3G. Next point is to exploit multiuser diversity. It also deals efficiently with frequency- that 4G will provide quality of service and security to the end users. selective fading without the need for a complicated equalizer. OFDM This feature has been lacking in 3G networks. And the last one is that has a high degree of flexibility of radio resource management. It IP-based multimedia services such as Voice over IP (VoIP) and video provides different frequency responses of different channels for various streaming are expected to be the major traffic types in 4G networks users, data rate adaptation over each subcarrier, dynamic sub-carrier [6,7]. assignment and adaptive power allocation. Long Term Evolution (LTE) was introduced in 3GPP (3rd OFDM suffers in some aspects also. One of the major drawbacks J Elec Electron ISSN: 2167-101X JECEC an open access journal Volume 1 • Issue 3 • 1000104 Citation: Rathore AK, Chaurasia RK, Mishra R, Kumar H (2012) Road Map and Challenges in 4G Wireless System. J Elec Electron 1:104. doi:10.4172/2167-101X.1000104 Page 3 of 4 battery power for transmitting the entire video are saved. Here it plays Reality level a significance role in 4G wireless communications. Hologram Content based interactivity is highly connected to UMA. It 3D also imposes higher expectations and requirements on content Multi - view understanding supports. In the 4G wireless system, the mobile television Stereo user may customize the content by manipulating the text, image, audio, video and graphics. As this system is high speed system so the user Single - view may even access information that is not available and supported in the Stereo current system. The 4G wireless system is going to face a challenge for 2D the watching movie or television in a new user experience with much TV, Phone higher interactivity. Also video on TV will not be flat for much longer 2G 3G 4G time. The next step forward is three dimension (3D) video / TV services over 4G wireless networks with various representations [13]. The trend 1990 2000 2005 2010 2015 is shown in figure 2 below. At present the stereophonic and multi-view Figure 2: Estimated reality video over wireless networks. 3D videos are more developed than other 3D video representation formats owing to the standardized MPEG in coding approaches. of it is that signals have a large peak to average power ratio. This ratio Normally 3D video takes 1.5 times bit rate as required by 2D video, but increases approximately linearly with the number of subcarriers. Large using efficient coding, such as sub-band based coding, the coded 3D peak to average power ratio force the transmitter power amplifier to video takes a 1.2 bit rate as compared to traditional 2D video [14-16]. have a large backoff in order to ensure the linear amplification of the Therefore higher reality requirements will bring a larger volume of data signal. The high peak to average power ratio of OFDM is reduced by to be delivered over the network. This in addition to more services and clipping the OFDM signal above some threshold, peak cancellation user scenarios are the challenges for 4G wireless systems. with a complementary signal, allowing nonlinear distortion from the Cross-layer design mechanism plays a critical role in order to power amplifier and special coding techniques. Also OFDM systems supply so many applications and services with quality of service in are highly sensitive to frequency offsets caused by the oscillator 4G networks. In the cross layer design the interactions between the inaccuracies and the Doppler shift due to mobility, which gives rise different network protocol layers can be optimized jointly in end-to- to inter-carrier interference. Methods of reducing frequency offset end system. This is done in order to achieve better performance. The effects include windowing of the transmitted signal, self interference content delivery with satisfactory quality of user experience becomes cancellation schemes and frequency offset estimation methods. an important issue. Challenges and Opportunities Conclusion It may be expected that in 4G the communication networks will Currently 4G wireless communication systems are still in their continue to expand. It will include all kinds of channels with various information, quality of service and protocols. It will also contain planning phase. The new infrastructure is expected to provide much all heterogeneous terminals with a diverse range of capabilities, higher data rates, lower cost per transmitted bit, more flexible mobile accessibilities and user preferences. The world today is moving to a terminals, and seamless connections to different networks. In this content producer. Uploading one’s piece of work onto the network and paper, we introduced the features of 4G, and also point out the short enjoying the work of other is the trend. The gap between the richness coming of the existing technology. 4G seems to be the interesting of multimedia content and the variation of techniques for content technology which the world is looking forward. It is also a cardinal one access and delivery will increase dramatically. Expectation of universal to the emerging mobile phones, and has many unique features. High multimedia access (UMA) will be a challenge for the 4G wireless speed multimedia based services are its essential features. 4G wireless networks [12]. The major concept of UMA is universal or seamless networks provide many features to handle the current challenges in access to multimedia content by automatic selection or adaption of video communications. Content delivery will play a major role here. content. A demand for a larger volume of data to be delivered over the network is the priority. These services entangled with user scenarios are the Content analysis refers to intelligent computational techniques. It challenges for 4G wireless systems. extracts information automatically from a recorded video sequence/ image. From such analysis, the machine is able to discover what is References presented in the scene, who is there and where or when it occurs. 1. Rappaport TS (1996) Wireless Communications: Principles and Practice. As people have become more and more enthusiastic about watching Prentice Hall PIR. multimedia content using mobile devices, so they personalize the 2. Chia JB (2002) Video services over 4G wireless networks: not necessarily content by summarizing the video for easy retrieval or for easy Streaming. Wireless Communications and Networking Conference, 2002. WCNC2002. 2002 IEEE 1: 18 - 22. transmission. 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