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Fifth-generation (5G) networks are evolving from special purpose-built networks to software-defined, intelligent, multipurpose networks, enabling service innovation and autonomous network operation. In this article, we present an intelligent mobile edge network based on standardized 5G network function entities and New Radio (NR) radio access networks (RANs). We propose a multitier, self-organizing network (SON) with a middle-tier SON (mSON), centralized SON (cSON), and distributed SON (dSON) to support increasing network dynamicity for different verticals and to take advantage of the latest high-layer F1 interface. This is essential to support low-latency applications and ultrahigh-reliability services. It also enables more dynamically tight interworking of 5G NR and LTE with dual connectivity, expanding initial 5G NR coverage. We analyze a lower-layer RAN split to optimize fronthaul and so further improve radio efficiency by utilizing the multitier SON among various radio nodes as well as distributed units (DUs) and centralized units (CUs). This will facilitate massive multiple-input/multiple-output (MIMO) antenna systems and accelerate centralized and virtualized RAN deployments.

Motion-compensated fine-granularity scalability (MC-FGS) with leaky prediction has been shown to provide an efficient tradeoff between compression gain and error resilience, facilitating the transmission of video over dynamic channel conditions. In this paper, we propose an n-channel symmetric motion-compensated multiple description (MD) coding and transmission scheme for the delivery of scalable video over orthogonal frequency division multiplexed systems, utilizing the concepts of partial and leaky predictions. We investigate the proposed MD coding and transmission scheme using a cross-layer design perspective. In particular, we construct the symmetric motion-compensated MD codes based on the diversity order of the channel, defined as the ratio of the overall bandwidth of the system to the coherence bandwidth of the channel. We show that knowing the diversity order of a physical channel can assist an MC-FGS video coder in selecting the motion-compensation prediction point, as well as on the use of leaky prediction. More importantly, we illustrate how the side information can reduce the drift management problem associated with the construction of symmetric motion-compensated MD codes. We provide results based on both an information-theoretic approach and simulations.

We propose a model-based analytic approach for evaluating the overall efficacy of FEC coding combined with interleaving in combating packet losses in IP networks. In particular, by modeling the network path in terms of a single bottleneck node, described as a G/M/1/K queue, we develop a recursive procedure for the exact evaluation of the packet-loss statistics for general arrival processes, based on the framework originally introduced by Cidon et al., 1993. To include the effects of interleaving, we incorporate a discrete-time Markov chain (DTMC) into our analytic framework. We study both single-session and multiple-session scenarios, and provide a simple algorithm for the more complicated multiple-session scenario. We show that the unified approach provides an integrated framework for exploring the tradeoffs between the key coding parameters; specifically, interleaving depths, channel coding rates and block lengths. The approach facilitates the selection of optimal coding strategies for different multimedia applications with various user quality-of-service (QoS) requirements and system constraints. We also provide an information-theoretic bound on the performance achievable with FEC coding in IP networks.

In this article we investigate the trade-offs and the constraints for multimedia over mobile ad hoc CDMA networks, and propose a cross-layer distributed power control and scheduling protocol to resolve those trade-offs and constraints in order to provide high-quality video over wireless ad hoc CDMA networks. In particular, a distributed power control and scheduling protocol is proposed to control the incurred delay of video streaming over multihop wireless ad hoc networks, as well as the multiple access interference (MAI). We also investigate the impacts of Doppler spread and noisy channel estimates upon the end-to-end video quality, and provide a relatively robust system which employs a combination of power control and coding/interleaving to combat the effects of Doppler spread by exploiting the increased time diversity when the Doppler spread becomes large. Thus, more robust end-to-end video quality can be achieved over a wide range of channel conditions

We propose a joint source-coding power-control approach combined with joint source-channel coding employing the class of rate-compatible codes for video transport over code-division multiple-access networks. We show that this cross-layer approach can provide improved spectral efficiency and network use while exhibiting graceful degradation characteristics with an increasing number of users

We consider future generation wireless code-division multiple-access (CDMA) cellular networks supporting heterogeneous compressed video traffic and investigate transport schemes for maximizing the number of users that can be supported in a single cell while simultaneously maximizing the reconstructed video quality of individual users. More specifically, we demonstrate that the network resources consumed by an individual user in a spread-spectrum CDMA network can be taken as the product of the allocated source-coding rate R/sub s/ and the energy per bit normalized to the multiple-access interference noise density /spl gamma//sub b/. We propose a joint source coding and power control (JSCPC) approach for allocating these two quantities to an individual user, subject to a constraint on the total available bandwidth, to simultaneously maximize the per-cell capacity while maximizing the quality of the delivered video to individual users. We demonstrate the efficacy of this approach using the ITU-T H.263+ video source coder, although the approach is generally applicable to other source-coding schemes as well. The results indicate a significant improvement in delivered quality-of-service (QoS), measured in terms of the end-user average peak signal-to-noise ratio, that can be achieved at a given level of network loading. Furthermore, we demonstrate that without an appropriate JSCPC strategy the traditional soft-capacity limit associated with CDMA networks is no longer present. Indeed, a precipitous decrease in performance can be expected with increasing load. We show that this behavior can be avoided with the proposed JSCPC approach, thereby significantly extending the useful capacity of the CDMA network while exhibiting a more graceful degradation pattern under increasing load.

Coding and diversity are very effective techniques for improving transmission reliability in a mobile wireless environ- ment. The use of diversity is particularly important for multimedia communications over fading channels. In this work, we study the transmission of progressive image bitstreams using channel coding in a 2-D time-frequency resource block in an OFDM network, em- ploying time and frequency diversities simultaneously. In partic- ular, in the frequency domain, based on the order of diversity and the correlation of individual subcarriers, we construct symmetric -channel FEC-based multiple descriptions using channel erasure codes combined with embedded image coding. In the time domain, a concatenation of RCPC codes and CRC codes is employed to pro- tect individual descriptions. We consider the physical channel con- ditions arising from various coherence bandwidths and coherence times, leading to a range of orders of diversities available in the time and frequency domains. We investigate the effects of different error patterns on the delivered image quality due to various fade rates. We also study the tradeoffs and compare the relative effec- tiveness associated with the use of erasure codes in the frequency domain and convolutional codes in the time domain under different physical environments. Both the effects of intercarrier interference and channel estimation errors are included in our study. Specifi- cally, the effects of channel estimation errors, frequency selectivity and the rate of the channel variations are taken into consideration for the construction of the 2-D time-frequency block. We provide results showing the gain that the proposed model achieves com- pared to a system without temporal coding. In one example, for a system experiencing flat fading, low Doppler, and imperfect CSI, we find that the increase in PSNR compared to a system without time diversity is as much as 9.4 dB.

In this paper, we study multiple description (MD) coding and transport for real-time video using multiple asymmetric paths in a packetized network. In particular, we construct the motion- compensated (MC) MD codes using MC-FGS video coder, based on the statistical characteristics and the asymmetry of the multiple routing paths. The MCMDs are the optimally allocated to the multiple paths to minimize the end-to-end video distortion. Simulation results demonstrate that the proposed video transport system can achieve improved performance in both end user quality-of-service and error resilience.

Coding and diversity are very effective techniques for improving transmission reliability in a mobile wireless environment. The use of diversity is particularly important for multimedia communications over fading channels. In this work, we study the transmission of progressive image bitstreams using channel coding in a 2-D time-frequency resource block in an OFDM network, employing time and frequency diversities simultaneously. In particular, in the frequency domain, based on the order of diversity and the correlation of individual subcarriers, we construct symmetric ra-channel FEC-based multiple descriptions using channel erasure codes combined with embedded image coding. In the time domain, a concatenation of RCPC codes and CRC codes is employed to protect individual descriptions. We consider the physical channel conditions arising from various different coherence bandwidths and coherence times, leading to various orders of diversities available in the time and frequency domains. We also study the tradeoffs and the relative effectiveness associated with the use of erasure codes in the frequency domain and convolutional codes in the time domain under different physical environments.

Bursty packet losses can be quite harmful to video applications transmitted over the Internet since burst losses generally produce a larger video distortion than an equal number of isolated losses [1]. This paper combines packet interleaving with motion-compensated (MC) fine granularity scalability (MC-FGS) video source coding and unequal loss protection (ULP) to combat the effects of bursty losses. The video source coder, ULP allocation and interleaver parameters are jointly optimized under an end-to-end delay constraint based on the network state. The simulation results demonstrate that the improvement in mean PSNR achieved by this proposed scheme increases as the average burst length of the network losses increases or the delay constraint is relaxed. For a short media clip, this system can achieve 1.9 dB improvement over a comparison transport system without interleaving.

We propose an n-channel symmetric motion-compensated multiple description (MD) coding and transmission scheme for the delivery of fine granular scalable (FGS) video over multicarrier orthogonal frequency division multiplexing (OFDM) systems, utilizing the concepts of partial and leaky predictions. We investigate the proposed MD coding and transmission scheme using a cross-layer design perspective. In particular, we construct the symmetric motion compensated MD codes based on the diversity order of the channel, defined as the ratio of the overall bandwidth of the system to the coherence bandwidth of the channel. We show that knowing the diversity order of a physical channel can assist an FGS video coder in selecting the motion compensation prediction point, as well as on the use of leaky prediction. More importantly, we illustrate how the side information can reduce the drift management problem associated with the construction of symmetric motion-compensated MD codes.

Diversity can be used to combat multipath fading and improve the performance of wireless multimedia communication systems. In this work, by considering transmission of an embedded bitstream over an orthogonal frequency division multiplexing (OFDM) system in a slowly varying Rayleigh faded environment, we develop a cross-layer diversity technique which takes advantage of both multiple description coding and frequency diversity techniques. More specifically, assuming a frequency-selective channel, we study the packet loss behavior of an OFDM system and construct multiple independent descriptions using an FEC-based strategy. We provide some analysis of this cross-layer approach and demonstrate its superior performance using the set partitioning in hierarchical trees image coder.

In wireless networks, channel state information is hard to obtain in a reliable and timely manner due to the rapid change of wireless environments. In this paper we propose instead the use of source information, which is always available at the encoder and can be easily and accurately obtained from video sequences, to achieve error-resilience. With use of exponential weighted moving average (EWMA) estimation for the motion-level information associated with video frames, a source-adaptive intra-coding rate selection scheme is described to provide error-resilience to N successive video frames. Based on our proposed cross-layer packetization scheme, a novel intra-frame packet interleaving scheme is implemented together with a fixed FEC coding strategy at the application-layer to combat the severe bursty losses over wireless channels, and the performance of the combined approach is investigated. Our objective and subjective results demonstrate the effectiveness of our approach in dealing with the bursty packet losses on both wireless single-hop and multi-hop networks without any additional system complexity or delay.

Diversity can be used to combat multipath fading and improve the performance of mobile wireless multimedia communication systems. In this work, by considering transmission of an embedded bitstream over a slow varying Rayleigh faded environment, we develop a cross-layer diversity technique which takes advantage of both multiple description source coding and frequency diversity techniques. More specifically, assuming a frequency-selective channel, we study the packet loss behavior of an OFDM system and construct multiple independent descriptions using an FEC-based strategy. We demonstrate the superior performance of this approach using the set partitioning in hierarchical trees (SPIHT) coder.

We study a problem in cross-layer optimization for video delivery over CDMA networks. By considering the resource requirements as the aggregate of the products of source coding rates and the energy per information bit to noise ratio, we propose a joint source coding-power control (JSCPC) strategy combined with joint source-channel coding (JSCC) employing the class of rate-compatible punctured turbo (RCPT) codes to provide forward error correction with unequal error protection (FEC/UEP). We show that this cross-layer approach can simultaneously maximize the quality of the delivered video while minimizing the total resource consumption, thereby providing improved spectral efficiency and network utilization. We demonstrate the efficacy of this approach using the ITU-T H.263+ video source coder.

We study a problem in cross-layer adaptation and optimization for multimedia delivery over IP-based CDMA cellular networks. By considering the resource requirements as the aggregate of the products of source coding rates and the energy per information bit to noise ratio, we propose a joint source coding-power control (JSCPC) strategy combined with joint source-channel coding (JSCC) to simultaneously maximize the quality of the delivered video while minimizing the total resource consumption. We concentrate on the use of the RTP/UDP/IP transport protocol and incorporate the network adaptive features of the H.264/AVC coder and show that the proposed approach can provide both improved spectral efficiency and network utilization.

We investigate multicast/broadcast of digital video over spread-spectrum CDMA cellular networks, a platform targeted at various kinds of multimedia services. In particular, we propose an end-to-end embedded transmission scheme which combines a scalable video source coder, adaptive power allocation, adaptive channel coding and an embedded multiresolution modulation strategy to simultaneously deliver a basic quality-of-service (QoS) to less capable receivers and an enhanced QoS for more capable receivers. We demonstrate the efficacy of this approach using the ITU-T H.263+ video source coder, although the approach is generally applicable to other scalable source coding schemes as well.

We consider a cross-layer design approach for CDMA mobile wireless networks supporting heterogeneous compressed video. By considering the resource requirements as the aggregate of the products of source coding rates and the energy per information bit to noise ratio, we propose a cross-layer optimization approach for video delivery over CDMA cellular networks. In particular, we describe a joint source coding-power control (JSCPC) strategy used in conjunction with joint source-channel coding (JSCC) and employing the class of rate-compatible punctured convolutional (RCPC) codes to provide forward error correction (FEC) coding. We show that this cross-layer approach can simultaneously maximize the quality of the delivered video while minimizing the total resource consumption, thereby providing higher spectral efficiency and improved network utilization. We demonstrate the efficacy of this approach using the ITU-T H.263+ video coder.

We investigate the transport of scalable digital video over future third-generation (3G) wireless CDMA cellular systems By considering the resource requirements as the aggregate of the products of source coding rates and the energy per information bit to noise ratio, we propose a joint source coding and power control (JSCPC) scheme which simultaneously maximizes the quality of the delivered video while minimizing the total resource consumption. We demonstrate the efficacy of this approach using the ITU-T H.263+ video source coder, although the approach is generally applicable to other source coding schemes as well.

We study a cross-layer optimisation approach for the transport of packetised digital video over future generation CDMA mobile wireless networks, taking into account both the interference-limited and bandwidth-limited characteristics associated with spread-spectrum CDMA systems. In particular, by considering the resource requirements as the aggregate of the products of source coding rates and the energy per information bit to noise ratio, we propose a joint source coding-power control (JSCPC) strategy combined with adaptive channel coding employing the class of rate-compatible punctured turbo (RCPT) codes to provide forward error correction (FEC) with unequal error protection (UEP). We show that this adaptive cross-layer approach can simultaneously maximise the quality of the delivered video while minimising the total resource consumption, thereby providing improved spectral efficiency and network utilisation. We demonstrate the efficacy of this approach using the ITU-T H.263+ video source coder although the approach is generally applicable to other source coding schemes as well.