Scheduling for Video Transmission in LTE Downlink

Abstract

Initial developments of cellular networks were intended for voice only applications. Later the need to support several applications and services lead to the evolution of mobile technology. In order to meet the growing user demands and high data rate requirements the fourth generation of mobile communication has adopted a standard called LTE. LTE provides high data rates, flexible bandwidth usage and low latency in networks. Scheduling is a feature employed at the eNodeB to allocate user equipments with available resources in the most efficient way. A scheduling scheme for video transmission is proposed in the downlink. A decision index is introduced in the algorithm which considers the status of the transmission queue and the quality of the channel connecting the eNodeB and the intended user equipment. Higher decision indexed valued user data is scheduled first. Index Terms: 4G, LTE, Video Codec, H.264, Resource Block, Channel Quality, CQI, Scheduling. I. Introduction Individuals exchange information between them through the process of communication. Communication can be done by any means such as gestures, vocabulary, written scripts and wired or wireless means. Nowadays wireless communication systems play a vital role in revolutionizing the means of information exchange. Mobile Communication categorically falls into the division of wireless communication. It is now one of the fastest means for conveying information between individuals. Mobile technology has evolved from the usage of analog devices to the digital counter parts. From first generation (1G) of mobile communication to the forthcoming fifth generation (5G) the difference in communication speed and bandwidth flexibility is clearly visible. Amplitude and frequency modulation techniques employed in the zeroth generation of mobile technology gave only a handful of channels for communication. Analog devices were designed for voice only applications in 1G which gave only low capacity voice channels. Later with digital techniques and multiple access schemes 2G provided unlimited access to limited channels. Wider range of applications such as voice telephony, video call, mobile TV, GPS (Global Positioning System) and video conferencing were supported by the third generation (3G) of mobile communications. However with the advent of newer technologies and a hike in user demands, the need for next generation of mobile technology became inevitable. Thus the evolution of fourth generation mobile technology occurred. 4G is clearly an improvement from its pre-existing technologies in terms of spectral efficiency, data rates and network capacity. LTE is the wireless standard adopted by the fourth generation of mobile technology. The adaptive modulation and coding (AMC) schemes, MIMO antenna technique and multicarrier modulation schemes such as OFDM jointly contributes to the high achievable data rates and spectral efficiency (3). In LTE systems, scheduling and resource allocation are the two important features adopted to ensure user satisfaction as well as efficient utilization of the available spectrum. Scheduling ensures the proper transmission and reception of the most urgent user data in the queue. Assignment of radio resources to users based on their quality of service (QoS) requirements and quality of the communication links is the main function of the scheduling and resource allocation processes.