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Joint source/channel coding of wwan multicast video for a cooperative peer-topeer collective using structured network coding
, 2009
"... Abstract—Because of frequent wireless packet losses and inapplicability of retransmission-based schemes due to the wellknown NAK implosion problem, providing high quality video multicast over Wireless Wide Area Networks (WWAN) remains difficult. Traditional joint source/channel coding schemes for vi ..."
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Abstract—Because of frequent wireless packet losses and inapplicability of retransmission-based schemes due to the wellknown NAK implosion problem, providing high quality video multicast over Wireless Wide Area Networks (WWAN) remains difficult. Traditional joint source/channel coding schemes for video multicast—optimal bit allocation among source coding and channel coding such as Forward Error Correction (FEC) subject to a bitrate constraint—target a chosen nth-percentile WWAN user. Not only is FEC bitwise expensive, users with poorer reception than nth-percentile user suffer substantial channel losses, while users with better reception have more channel coding than necessary, meaning too few bits are devoted for source coding to reduce quantization noise and sub-optimal video quality. Instead, in this paper we perform joint source/channel coding of WWAN video multicast for an entire collective of multi-homed ad-hoc peers in the same multicast group and connected via Wireless Local Area Networks (WLAN). In a cooperative peerto-peer repair (CPR) scenario, after each peer received a different subset of WWAN packets, the peer group repairs WWAN losses locally by packet-forwarding to each other via WLAN. From an end-to-end system view, CPR means that a packet can be transmitted from source to a peer either via WWAN directly, or via WLAN local repairs exploiting neighboring peers ’ WWAN links; the overall more general transmission condition means a clever joint source/channel coding scheme can now allocate more bits to source coding without suffering more packet losses, leading to higher video quality. To efficiently implement both WWAN FEC and WLAN CPR repairs, we propose to use network coding for this dual purpose to reduce decoding complexity at the peers. We show through simulations that using our proposed scheme dramatically improves video quality over existing optimization scheme where joint source/channel coding was performed, but WLAN CPR was not used, by up to 8.4 dB, and over scheme when WLAN CPR and WWAN joint source/channel coding were performed separately by up to 4.4 dB.
Distributed source coding for WWAN multiview video multicast with cooperative peer-to-peer repair
- in IEEE International Conference on Communications
, 2011
"... Abstract—Video multicast over Wireless Wide Area Networks (WWAN) is difficult because of unavoidable packet losses and impracticality of retransmission on a per packet, per client basis, due to the known NAK implosion problem. Recent approach exploits clients ’ cooperation for packet recovery, so th ..."
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Abstract—Video multicast over Wireless Wide Area Networks (WWAN) is difficult because of unavoidable packet losses and impracticality of retransmission on a per packet, per client basis, due to the known NAK implosion problem. Recent approach exploits clients ’ cooperation for packet recovery, so that a peer group’s received WWAN packets are shared using a secondary network like Wireless Local Area Network (WLAN). For multi-view video multicast, where a client can switch views interactively by subscribing to different WWAN multicast channels streaming different views, two new difficulties arise. First, system must provide timely view-switching mechanism, so that client can switch to a desired view quickly for correct decoding and display. Second, it is difficult for system to leverage neighboring peers for cooperative loss recovery, since neighbors are more likely to be subscribing to different views from a loss-stricken peer. In this paper, we use Distributed Source Coding (DSC), a new compression tool in video coding, to solve both problems. Each DSC frame is encoded with a set of predictor frames, and correct decoding only requires one of the predictors in the set to be available at decoder. Periodic insertion of DSC frames into video streams then enables a peer to switch from view v to v ′ at the DSC frame boundary, assuming DSC frame of view v ′ was encoded using a frame in view v as a predictor. For the same assumption, a neighbor watching view v can help a peer watching view v ′ evade error propagation resulting from earlier losses and resume decoding at the DSC boundary. Experiments show that optimized usage of DSC frames in a coding structure, where unequal error protection is enabled to decrease the probability of decoding failure earlier in a group of pictures, outperforms a structure using I-frames instead for view switching by up to 11dB in video quality in typical WWAN network loss environment. I.
Rate-distortion Optimized Joint Source/Channel Coding of WWAN Multicast Video for A Cooperative Peer-to-Peer Collective
"... Abstract—Because of unavoidable wireless packet losses and inapplicability of retransmission-based schemes due to the wellknown NAK implosion problem, providing high quality video multicast over Wireless Wide Area Networks (WWAN) remains difficult. Traditional joint source/channel coding (JSCC) sche ..."
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Abstract—Because of unavoidable wireless packet losses and inapplicability of retransmission-based schemes due to the wellknown NAK implosion problem, providing high quality video multicast over Wireless Wide Area Networks (WWAN) remains difficult. Traditional joint source/channel coding (JSCC) schemes for video multicast target a chosen nth-percentile WWAN user. Users with poorer reception than nth-percentile user (poor users) suffer substantial channel losses, while users with better reception (rich users) have more channel coding than necessary, resulting in sub-optimal video quality. In this paper, we recast the WWAN JSCC problem in a new setting called Cooperative Peer-to-Peer Repair (CPR), where users have both WWAN and Wireless Local Area Network (WLAN) interfaces and use the latter to exchange received WWAN packets locally. Given CPR can mitigate some WWAN losses via cooperative peer exchanges, a CPR-aware JSCC scheme can now allocate more bits to source coding to minimize source quantization noise without suffering more packet losses, leading to smaller overall visual distortion. Through CPR, this quality improvement is in fact reaped by all peers in the collective, not just a targeted nth-percentile user. To efficiently implement both WWAN FEC and WLAN CPR repairs, we propose to use network coding for this dual purpose to reduce decoding complexity and maximize packet recovery at the peers. We show that a CPRaware JSCC scheme dramatically improves video quality: by up to 8.7dB in Peak Signal-to-Noise Ratio (PSNR) for the entire peer group over JSCC scheme without CPR, and by up to 6.0dB over a CPR-ignorant JSCC scheme with CPR.
Deterministic structured network coding for wwan video broadcast with cooperative peer-to-peer repair
- in Proceedings of the International Conference on Image Processing (ICIP
, 2010
"... Recent research has exploited the multi-homing property (one terminal with multiple network interfaces) of modern devices to improve communication performance in wireless networks. Cooperative Peer-to-peer Repair (CPR) is one example where given simultaneous connections to both a Wireless Wide Area ..."
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Recent research has exploited the multi-homing property (one terminal with multiple network interfaces) of modern devices to improve communication performance in wireless networks. Cooperative Peer-to-peer Repair (CPR) is one example where given simultaneous connections to both a Wireless Wide Area Network (WWAN) and an ad-hoc Wireless Local Area Network (WLAN), peers receiving different subsets of WWAN broadcast packets can exchange received WWAN packets with their ad-hoc WLAN peers for local recovery. In our previous work, we have shown that by using Network Coding (NC) to linearly combine received packets into new CPR packets for local exchanges, packet recovery can be improved. Moreover, by imposing Structure on Network Coding (SNC) when encoding a CPR packet, decoding of at least the important packets becomes possible in the event when insufficient number of CPR packets were received for full recovery. Given SNC is used during CPR, the key decision for each peer is to determine which SNC type to encode a repair packet at each WLAN transmission opportunity. The decision is further complicated by the observation that peers in general receive different numbers of CPR packets from neighbors due to varying amount of WLAN link contentions and interference experienced. In this paper, we propose a novel counter-based deterministic SNC type selection scheme. Using this approach, we show that a simple local optimization procedure, taking advantage of available neighbors ’ state information, can be easily implemented to further improved CPR performance. Simulation results show that our proposed scheme outperformed our previous randomized SNC type selection scheme by up to 1.87dB. Index Terms — WWAN video broadcast, cooperative peer-topeer repair, structured network coding 1.
REDUNDANT REPRESENTATION FOR NETWORK VIDEO STREAMING USING RECONSTRUCTED P-FRAMES AND SP-FRAMES
"... For low-delay streaming of pre-encoded video over lossy net-works, fast recovery from decoding errors typically involves use of frequent intra-coded frames, which incurs high bandwidth cost. In this paper, we present a redundant representation of video us-ing a bandwidth-efficient but non-resilient ..."
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For low-delay streaming of pre-encoded video over lossy net-works, fast recovery from decoding errors typically involves use of frequent intra-coded frames, which incurs high bandwidth cost. In this paper, we present a redundant representation of video us-ing a bandwidth-efficient but non-resilient main bitstream, and an additional auxiliary bitstream dedicated to recovery from losses in the main bitstream. In particular, we insert primary SP-frames periodically into the main bitstream, and encode corresponding secondary SP-frames and reconstructed P-frames in the auxiliary stream. When a frame loss occurs, a reconstructed P-frame is first sent to re-synchronize decoder back to normal motion compensation loop, then a secondary SP-frame corresponding to the location of the next pre-inserted primary SP-frame in the main stream is sent there-after, eliminating coding drift. Results show that proposed method out-performs non-redundant representation of I-frame insertion by up to 11 frames in recovery time, and out-performed redundant representation of only reconstructed P-frames by up to 2.2dB in average PSNR. Index Terms — Video streaming, SP-frames, redundant repre-sentation
DiCoR: Distributed Cooperative Repair of Multimedia Broadcast Losses
"... allows a common broadcast channel to be shared by users interested in identical content. We explore the problem of enhancing MBMS resilience by repairing packets lost during broadcast. Since MBMS broadcast consumes expensive 3G resources, we leverage the ubiquity of multi-homed mobile devices i.e., ..."
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allows a common broadcast channel to be shared by users interested in identical content. We explore the problem of enhancing MBMS resilience by repairing packets lost during broadcast. Since MBMS broadcast consumes expensive 3G resources, we leverage the ubiquity of multi-homed mobile devices i.e., devices having both cellular and IEEE 802.11 wireless interfaces. We thus accomplish out-of-band repair of MBMS packet losses through an ad-hoc, peer-to-peer 802.11-based network. A fundamental challenge in scheduling repair transmissions is handling interference between distributed nodes. We present DiCoR, a fully distributed protocol for CPR. Our protocol does not assume any a priori knowledge of the network topology or peer losses, and is resilient to dynamic network changes due to node mobility or the continuous joining and leaving of peers. Detailed simulation experiments, under realistic loss models and network conditions, demonstrate that DiCoR presents a viable solution for timely out-of-band loss repair of MBMS real-time broadcast. I.
BIT ALLOCATION OF WWAN SCALABLE H.264 VIDEO MULTICAST FOR HETEROGENEOUS COOPERATIVE PEER-TO-PEER COLLECTIVE
"... By exploiting multiple network interfaces on one device, e.g., Wireless Wide Area Network (WWAN) and Wireless Local Area Network (WLAN), peers receiving different subsets of WWAN broadcast/multicast packets can perform Cooperative Peer-to-peer Repair (CPR) by exchanging received WWAN packets with th ..."
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By exploiting multiple network interfaces on one device, e.g., Wireless Wide Area Network (WWAN) and Wireless Local Area Network (WLAN), peers receiving different subsets of WWAN broadcast/multicast packets can perform Cooperative Peer-to-peer Repair (CPR) by exchanging received WWAN packets with their local WLAN peers. This effectively improves the transmission success from a WWAN broadcast/multicast source to a CPR collective. In this paper, we propose an intelligent joint source/channel bit allocation scheme for WWAN scalable video multicast that leverages on the CPR paradigm. Key observation is that given a peer can successfully receive a packet either from the WWAN channel directly, or via a CPR neighbor using ad-hoc WLAN connections, more bits can be redistributed from channel to source coding out of a fixed WWAN bit budget to further minimize peer’s expected visual distortion. In our proposal, groups of peers requiring different video resolutions are assigned to the same multicast group, and we perform one WWAN resource allocation and subsequent CPR over heterogeneous peers of different resolutions together. Our simulations show that our joint multicast group optimization can improve video quality by up to 2.84 dB, compared to a scheme where both WWAN resource allocation and WLAN CPR are separately performed for heterogeneous peers. 1.
Studies Doctoral Thesis Error Resilient Multi-view Video Streaming
, 2014
"... To my parents and sister ii Video is becoming more and more popular. Traditional video streaming only allows users passively receive and playback the video, without any freedom to select the view-ing angles. But users tend to change the viewing angles during the video playback especially when watchi ..."
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To my parents and sister ii Video is becoming more and more popular. Traditional video streaming only allows users passively receive and playback the video, without any freedom to select the view-ing angles. But users tend to change the viewing angles during the video playback especially when watching the sports events, etc. How to provide users the freedom to select favorite viewing angles becomes an important issue. Interactive multi-view video streaming (IMVS), which offers viewers the freedom to switch to a desired neighbor-ing captured view periodically, and free viewpoint video streaming (FVV), which offers viewers the freedom to choose any viewing angle between the left-most and right-most camera are two types of multi-view video streaming, which could satisfy users ’ view switch requests. By providing users this freedom, multi-view video is fast becoming the core technology for a number of emerging applications such as free viewpoint TV and is expected to be the next generation of visual communication. One fundamental research
Rate-Distortion Optimized Joint Source/Channel Coding of WWAN Multicast Video for A Cooperative Peer-to-Peer Collective
, 2009
"... Abstract—Because of unavoidable wireless packet losses and inapplicability of retransmission-based schemes due to the well-known negative acknowledgment implosion problem, providing high quality video multicast over wireless wide area networks (WWAN) remains difficult. Traditional joint source/chann ..."
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Abstract—Because of unavoidable wireless packet losses and inapplicability of retransmission-based schemes due to the well-known negative acknowledgment implosion problem, providing high quality video multicast over wireless wide area networks (WWAN) remains difficult. Traditional joint source/channel cod-ing (JSCC) schemes for video multicast target a chosen nth-percentile WWAN user. Users with poorer reception than nth-percentile user (poor users) suffer substantial channel losses, while users with better reception (rich users) have more channel coding than necessary, resulting in sub-optimal video quality. In this paper, we recast the WWAN JSCC problem in a new setting called cooperative peer-to-peer repair (CPR), where users have both WWAN and wireless local area network (WLAN) interfaces and use the latter to exchange received WWAN packets locally. Given CPR can mitigate some WWAN losses via cooperative peer exchanges, a CPR-aware JSCC scheme can now allocate more bits to source coding to minimize source quantization noise without suffering more packet losses, leading to smaller overall visual distortion. Through CPR, this quality improvement is in fact reaped by all peers in the collective, not just a targeted nth-percentile user. To efficiently implement both WWAN forward error correction and WLAN CPR repairs, we propose to use network coding for this dual purpose to reduce decoding complexity and maximize packet recovery at the peers. We show that a CPR-aware JSCC scheme dramatically improves video quality: by up to 8.7 dB in peak signal-to-noise ratio for the entire peer group over JSCC scheme without CPR, and by up to 6.0 dB over a CPR-ignorant JSCC scheme with CPR. Index Terms—Cooperative peer-to-peer repair, joint source-channel coding, network coding. I.
