The emerging 60-GHz multigigabits per second wireless technology enables the streaming of high-quality “uncompressed” video, which has been impossible with other existing wireless technologies. To support such a resource-hungry uncompressed video streaming service with limited wireless resources, it is necessary to design efficient link adaptation policies selecting suitable transmission rates for the 60-GHz wireless channel environment, thus optimizing video quality and resource management. For proper design of the link adaptation policies, we propose a new metric, called expected peak signal-to-noise ratio (ePSNR), to numerically estimate the video streaming quality. By using the ePSNR as a criterion, we propose two link adaptation policies with different objectives considering unequal error protection (UEP). The proposed link adaptation policies attempt to 1) maximize the video quality for given wireless resources, or 2) minimize the required wireless resources, while meeting the video quality. From the link adaptation policies, we provide a distributed resource management scheme for multiple users to maintain satisfactory video streaming quality. Our extensive simulation results demonstrate that the newly proposed variable, i.e., ePSNR, well represents the level of video quality. It is also shown that the proposed link adaptation policies can enhance the resource efficiency while achieving acceptable quality of the video streaming.

In this paper, overflow-aware rate control (OARC) algorithm for wireless networks is proposed to overcome the limitation of the TCP friendly rate control (TFRC) which is widely accepted congestion control scheme for multicast transmission over wired networks, by estimating the loss from channel error and the loss from buffer overflow separately. Proposed algorithm is evaluated by the comparison with TFRC on real wireless environment with 40 Samsung Galaxt tablets, and experiment results show that the proposed scheme had the maximum 304% higher good-put than TFRC.

Considerable efforts to improve the performance of multicast communication have been rarely successful in wireless network due to wireless channel nature. In this paper, we propose a reliable multicast engine considering both QoS and throughput enhancement. It includes 1) Application-layer Hybrid FEC/ARQ, 2) Adaptive FEC code rate control, 3) Feedback implosion avoidance, 4) Low-latency fast retransmission, 5) QoS-enhanced Buffer control, and 6) Overflow-aware source rate control (OARC) schemes. The proposed engine are evaluated on real environments with android mobile devices, and experiment results show that the proposed multicast engine had remarkable performance in term of good-put, delivery ratio and latency.

Forward Error Correction (FEC) can be exploited to realize reliable video multicast over Wi-Fi with high video quality. We propose reliable video multicast over Wi-Fi networks with coordinated multiple Access Points (APs) to enhance video quality. By coordinating multiple APs, each AP can transmit entirely or partially different FEC-encoded packets so that a multicast receiver can benefit from both spatial and time diversities. The proposed schemes can enlarge the satisfactory video multicast region by exploiting the AP diversity, thus serving more multicast receivers located at cell edge with satisfactory video quality. We propose a resource-allocation algorithm for FEC-code rate adaptation, utilizing the limited wireless resource more efficiently while enhancing video quality. We also introduce the method for estimating the video packet delivery ratio after FEC decoding. The effectiveness of the proposed schemes is comparatively evaluated via extensive simulation and experimentation. The proposed schemes are observed to enhance the ratio of satisfied users by up to 37.1% compared to the conventional single AP multicast scheme.