Yi-Mao Hsiao

A remote thin client system for real time multimedia streaming over VNC

This paper proposes a remote thin client system for real time multimedia streaming over VNC. A remote frame can be split as two parts, i.e. high motion part and low motion part, and transmitted through the Internet from servers to clients according to the proposed hybrid RTP protocol. A Dynamic Image Detection Scheme (DIDS) is proposed to automatically detecting the high motion part of a frame with only 1% of extra CPU loading. In addition, an Error Detection Scheme (EDS) and a Dynamic Bit-rate Control Scheme (DBCS) are also proposed to ensure good video streaming quality under bandwidth limited applications. This paper also proposes a linear time BU-level rate control algorithm to ensure the proposed DBCS can be finished in real time. The proposed algorithm reduces the computational complexity from O(n2)to be O(n). By using the proposed thin client system, we can achieve about 22 fps of real-time SIF video streaming with good video quality under 32 KByte/s of bandwidth limitation, which speeds up about 172 times in remote frame display when compared to pure VNC.

Review: H.264 video transmissions over wireless networks: Challenges and solutions

Multimedia video streaming is becoming increasingly popular. Using multimedia services, there are more and more users in end-system over wireless networking environment. H.264/AVC is now the standard for video streaming because of its high compression efficiency, robustness against errors and network-friendly features. However, providing the desired quality of service or improving the transmission efficiency for H.264 video transmissions over wireless networks present numbers of challenges. In this paper, we consider those challenges and survey existing mechanisms based on the protocol layers they work on. Finally, we address some open research issues concerning for H.264 video transmission in wireless networks.

A high-throughput and high-capacity IPv6 routing lookup system

With the growing number of routing entries, IP routing lookup has become the major performance bottleneck in backbone routers. In this paper, a complete hardware-based routing lookup system is proposed to achieve high-throughput and high-capacity for IPv6. The proposed system is a cache-centric, hash-based architecture that contains a routing lookup application specific integrated circuit (ASIC) and a memory set. A hash function is used to reduce lookup time for the routing table and ternary content addressable memory (TCAM) effectively resolves the collision problem. The gate count of the ASIC, excluding the binary content addressable memory (BCAM), is about 5306 gates, using an in-house 0.18@mm CMOS single-poly six-metal standard cell library. The results of post-layout simulations show that the ASIC operates in 3.6ns so that the routing lookup system approaches 260 Mega lookups per second (Mlps), which is sufficient for 100Gbps networks. The memory density is good, with each routing entry requiring only 64bits. Moreover, the routing table only needs 10.24KB on-chip BCAM, 20.04KB off-chip TCAM and 29.29MB DRAM for 3.6M routing entries in the proposed system.

Designing and implementing a scalable video-streaming system using an adaptive control scheme

Designing a real-time video-streaming system involves the challenges of, network congestion and bandwidth fluctuations, lowering the video quality. In this paper, a realtime video-streaming system is designed and implemented for scalable video coding (SVC) with an adaptive control scheme, containing macro- and micro-control, to resolve the bandwidth fluctuation and network congestion. Under macro-control, the server allocates appropriated video-streaming of SVC for heterogeneous clients based on terminal capacity and network conditions. Under micro-control, the server changes the video frame rate based on video bit rates and network bandwidth. The streaming system with the adaptive control scheme is implemented to improve the peak signal noise ratio (PSNR) by 4.01 % to 10.89 % of the Foreman and Stefan videos.

A design of bandwidth adaptive multimedia gateway for scalable video coding

Delivering multimedia streaming on Internet remains several limitations, such as bandwidth fluctuations and network conjunction. We present a multimedia gateway design including dynamic bandwidth estimation, SVC extractor and buffer management to resolve the limitations. The dynamic bandwidth estimation not only selects the appropriate SVC sub-stream, but also measures the change of bandwidth and packet loss with multimedia transmission. When the network congestion happened, the buffer management picks the important one from all packets. Weighted Random Early Detection (WRED) is used to increase peak signal-to-noise ratio (PSNR) of video stream. Comparing four WRED schemes, we figure out that “Disjoint” setting can get higher average of PSNR. The result shows that PSNR is elevated in the system proposed by us.

High speed UDP/IP ASIC design

With the growing of internet service, multimedia applications require higher communication speed. The network traffic has rapidly increased that produces amount of interrupts, memory copies and checksum calculation in end system. The CPU workload is heavy and the processing of network protocol task is the bottleneck. In this paper, we propose a UDP/IP ASIC to accelerate networking multimedia transmission. The checksum hardware just calculates packet header instead of whole packet with payload for UDP packet so that it can reduce the processing clock cycles for multimedia delivery. Besides, because of the Gigabit NIC support Jumbo Frame mostly, we figure out the packet size adopted 9Kbyte from which the performance is higher than the traditional 1.5KByte. As the results of simulation, the speed of the chip is 227.2MHz and the area is 0.936 * 0.733 mm2. The power consumption without SRAM is 7.21 mW. Therefore, the system throughput achieves 7.11Gbps that can deal with the traffic of Gigabit Ethernet in end system.

A fast update scheme for TCAM-based IPv6 routing lookup architecture

With the rapid development of the Internet applications and the explosion of end users, IP address has been exhausted and routing lookup speed is the bottleneck of router design. In addition TCAM is widely used for implementation fast IP forwarding table lookup. However, the need to maintain a sorted list incremental updates may slow the lookup speed in a TCAM. In this paper, a fast TCAM update scheme is proposed for TCAM-Based IPv6 routing lookup architecture. Based on the characteristic of prefix distribution, we design a TCAM-Based router architecture for IPv6 routing lookup. As simulation result shows more than 90% update do not need any memory movement in updating operation. The worse case is (D-2)/2, where D is the length of chain.

Design and implementation of a healthcare system with fall detection

Telemedicine information system becomes essential that healthcare system not only supports a better medicine care, but also reduces the medicine cost. In this paper, we introduce our design of outdoor patients monitoring system. This system monitors the patients whereabouts and then sends the patients physiological signals to the hospital. We implement a health-care box that collects ECG, video and location of the patient. The health-care box detects whether the patient fall by analyzing the collected information through GPS. Besides, we integrate the Google map into the healthcare system so that the user can know the location of the patient clearly. With proposed two thread system design, the improvements of detection time are 34%–39%.

High speed multimedia network ASIC design for H.264/AVC

With the growing of Internet service and users, multimedia video streaming application becomes more popular. There are two limitations: limited bandwidth affects high quality video delivery and high bit error ratio reduces system throughput. A packet with bit error is dropped in transport layer. H.264/AVC support high coding efficiency and network friendly. UDP-Lite is an idea that by pass packet with error bit to application layer. In this paper, we propose multimedia network ASIC that uses slice priority of NAL and partial checksum technique. Resolving two limitations, our ASIC can adaptive limited bandwidth to reduce packet loss and reduce packet drop in high bit error ratio environment that improves system throughput. Therefore, the ASIC increase transmission ability and network friendly for H.264/AVC codec. As post-layout simulation result shows, the ASIC operates at 455.5 MHz. The area is 0.337 × 0.315 mm2 and power consumption is 985.5679 uW. The system throughput achieves 14.58Gbps so that satisfies 10 Giga bit Ethernet.

Low power 32-bit UniRISC with Power Block Manager

In this paper we propose a low power technique named Power Block Manager (PBM) to reduce power consumption in various function units within a microprocessor. Power Block Manager considers each function block as an independent object. To disable running those function units which neither work nor affect the output results, the system can save the dynamic power dissipation. The PBM architecture involves three parts. The instruction type detector classifies the instructions. The power block table points out which power blocks can be turned on or off according to the instruction type. The scheduler arranges the power control signals to meet the pipelined system. We apply the PBM system to a 32-bit microprocessor named UniRISC which is designed by CCU SoC Center, and take three applications to examine the power. After the Post-Layout experiment, the processor with PBM system can save 20.1~30.2% power consumption.