Cheng-Hsin Hsu

Cheng-Hsin Hsu
National Tsing Hua University | NTHU · Department of Computer Science

About

102
Publications
17,489
Reads
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1,247
Citations
Citations since 2017
34 Research Items
534 Citations
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2017201820192020202120222023020406080
2017201820192020202120222023020406080

Publications

Publications (102)
Article
With the growth of Extended Reality (XR) and capturing devices, point cloud representation has become attractive to academics and industry. Point Cloud Compression (PCC) algorithms further promote numerous XR applications that may change our daily life. However, in the literature, PCC algorithms are often evaluated with heterogeneous datasets, metr...
Article
Nowadays, many Internet-of-Things (IoT) devices with rich sensors and actuators are being deployed to monitor community spaces. The data generated by these devices are analyzed and turned into actionable information by analytics operators. In this article, we present a Resource Efficient Adaptive Monitoring (REAM) framework at the edge that adaptiv...
Article
Surveillance videos in smart environments have become commodity nowadays, which enable many novel applications, including various video analytics that turn videos into semantic results. In addition to live feeds, the surveillance videos may be saved at a storage server for on-demand user-defined queries in the future. Different from on-demand video...
Article
Real-time screen-sharing provides users with ubiquitous access to remote applications, such as computer games, movie players, and desktop applications (apps), anywhere and anytime. In this article, we study the performance of different screen-sharing technologies, which can be classified into native and clientless ones. The native ones dictate that...
Article
Dynamic Adaptive Streaming over HTTP (DASH) has been widely used by several popular streaming services, such as YouTube, Netflix, and Facebook. Adopting DASH requires to pre-determine a set of encoding configurations, called encoding ladder, to generate a set of representations stored on the streaming server. These representations are adaptively re...
Conference Paper
Full-text available
Messaging and communication is a critical aspect of next generation Internet-of-Things (IoT) systems where interactions among devices, software systems/services and end-users is the expected mode of operation. Given the diverse and changing communication needs of entities, the data exchange interactions may assume different protocols (MQTT, CoAP, H...
Article
Head-mounted displays and 360° videos have become increasingly more popular, delivering a more immersive viewing experience to end users. Streaming 360° videos over the best-effort Internet, however, faces tremendous challenges, because of the high resolution and the short response time requirements. This survey presents the current literature rela...
Article
We study the problem of predicting the viewing probability of different parts of 360° videos when streaming them to Head-Mounted Displays (HMDs). We propose a fixation prediction network based on Recurrent Neural Network (RNN), which leverages sensor and content features. The content features are derived by Computer Vision (CV) algorithms, which ma...
Conference Paper
We design, implement, and evaluate a tiled DASH streaming system for 360° videos using QUIC/UDP protocol, in which multiplexed and prioritized streams are leveraged for sending urgent tiles that are about to miss their playout time. In particular, we develop a new architecture to concurrently request for regular tiled segments at a lower priority a...
Article
In this paper, we design and implement an Internet-of-Things (IoT) based platform for developing cities using environmental sensing as a driving application. Since ubiquitous and free WiFi access is not available in most developing cities, IoT deployments must leverage 3G cellular connections that are metered and expensive. In order to best utilize...
Conference Paper
With the skyrocketing amount of data communications, traditional Radio Access Networks (RANs) infrastructure suffers from high capital and operating expenditures. Many countries and mobile network operators, therefore, propose software-defined radio access networks for centralized management, and further apply cloud computing technologies into cell...
Conference Paper
After many devices that have adopted LTE technology, it is optimistic to presume that 5G technology will have to address the huge traffic of data and volume of heterogeneous devices in future. Existing context-aware Internet of Things (IoT) applications directly control sensors on LTE devices in an uncoordinated and non-optimized manner, which lead...
Article
In this article, we design a crowdsourcing system, CrowdMAC, where mobile devices form a local community or marketplace to share network access and transfer data for each other. CrowdMAC enables (i) mobile clients to select and exploit multiple mobile hotspots in its vicinity for data transfer and (ii) mobile hotspots to open their cellular connect...
Conference Paper
We consider the problem of efficiently using smartphone users to augment the stationary infrastructure sensors for better situation awareness in smart cities. We envision a dynamic sensing platform that intelligently assigns sensing tasks to volunteered smartphone users, in order to answer queries by performing sensing tasks at specific locations t...
Patent
Full-text available
The described system and method provide joint rate control and scalable stream adaptation for multiple clients concurrently competing for the same access networks. For each such client, an optimization problem is constructed and solved to determine the streaming rate over each access network, the video packets to be transmitted, and the access netw...
Article
We focus on the problem of efficient communications over access networks with asymmetric bandwidth and capability. We propose a resource-constrained asymmetric redundancy elimination algorithm (RCARE) to leverage downlink bandwidth and receiver capability to accelerate the uplink data transfer. RCARE can be deployed on a client or a proxy. Differen...
Conference Paper
IP multicast dictates high-end routers and incurs high administrative overhead, which prevent them from being deployed in many video streaming scenarios. In this paper, we study the problem of computing the multipath multicast routes for streaming videos in Software-Defined Networks (SDNs), which adopt less expensive switches and reduce administrat...
Conference Paper
In this paper, we explore the problem of supporting efficient access to social media contents on social network sites for mobile devices without requiring mobile users to be online all the time. We propose and implement a broker/proxy based architecture that stages data at a broker/proxy, and selectively downloads to the mobile device only those co...
Article
MultiNets is a system supporting seamless switch-over between wireless interfaces on mobile devices in real-time. MultiNets is configurable to run in three different modes: (i) Energy Saving mode--for choosing the interface that saves the most energy based on the condition of the device, (ii) Offload mode--for offloading data traffic from the cellu...
Article
We study the problem of disseminating videos to mobile users by using a hybrid cellular and ad hoc network. In particular, we formulate the problem of optimally choosing the mobile devices that will serve as gateways from the cellular to the ad hoc network, the ad hoc routes from the gateways to individual devices, and the layers to deliver on thes...
Conference Paper
Full-text available
In this paper, we consider the problem of efficient social media access on mobile devices, and propose an Offline Online Social Media (O2SM) Middleware to: (i) rank the social media streams based the probability that a given user views a given content item, and (ii) invest the limited resources (network, energy, and storage) on prefetching only tho...
Conference Paper
We design, implement, and evaluate an H.264/SVC decoder and an HTTP video streaming client on multi-core mobile devices. The decoder employs multiple decoder threads to leverage the multi-core CPUs, and the streaming server/client support adaptive HTTP video streaming. To evaluate the decoder performance, we conduct experiments using real H.264/SVC...
Conference Paper
Vehicular environments require continuous awareness of the road ahead. It is critical that mobile applications used in such environments (e.g., GPS route planners and location-based search) do not distract drivers from the primary task of operating the ...
Article
Recent popularity of smartphones drives rapid growth in the demand for cellular network bandwidth. Unfortunately, due to the centralized architecture of cellular networks, increasing the physical backhaul bandwidth is challenging. While content caching in the cellular network could be beneficial, relatively few characteristics of the cellular traff...
Article
We consider the problem of scalable video streaming from a server to multinetwork clients over heterogeneous access networks, with the goal of minimizing the distortion of the received videos. This problem has numerous applications including: 1) mobile devices connecting to multiple licensed and ISM bands, and 2) cognitive multiradio devices employ...
Conference Paper
We consider the decision engine of mobile cloud offloading systems, which decides whether to offload a given method to the cloud servers. We design, implement, and evaluate a context-aware decision algorithm, called CADA, to optimize the performance of the mobile devices with various optimization criteria, including short response time and low ener...
Article
We propose region- and action-aware virtual world clients. To develop such clients, we present a parameterized network traffic model, based on a large collection of Second Life traces gathered by us. Our methodology is also applicable to virtual worlds other than Second Life. With the traffic model, various optimization criteria can be adopted, inc...
Conference Paper
We design, implement, and evaluate a middleware system, HybCAST, that leverages a hybrid cellular and ad hoc network to disseminate rich contents from a source to all mobile devices in a predetermined region. HybCAST targets information dissemination over a range of scenarios (e.g., military operations, crisis alerting, and popular sporting events)...
Conference Paper
Today's mobile Internet is heavily overloaded by the increasing demand and capability of mobile devices, in particular, multimedia traffic. However, not all traffic is created equal, and a large portion of multimedia contents on the mobile Internet is delay tolerant. We study the problem of capitalizing the content transfer opportunities under bett...
Article
Full-text available
In this paper we present Multi Nets, a system which is capable of switching between wireless network interfaces on mobile devices in real-time. Multi Nets is motivated by the need of smart phone platforms to save energy, offload data traffic, and achieve higher throughput. We describe the architecture of Multi Nets and demonstrate the methodology t...
Article
Full-text available
This article presents the design of a complete, open-source, testbed for broadcast networks that offer mobile TV services. Although basic architectures and protocols have been developed for such networks, detailed performance tuning and analysis are still needed, especially when these networks scale to serve many diverse TV channels to numerous sub...
Article
Full-text available
We consider scalable video streaming from a base station over a hybrid cellular and ad hoc network to a large number of mobile devices. While such a system has been recently studied, existing efforts resort to simulations when evaluating their solutions, because there is no public-domain software for setting up a complete hybrid network testbed. In...
Conference Paper
Despite the successful use of local image features for large-scale object recognition, they are not effective in recognizing book spines on bookshelves. This is because some book spines contain only text components that do not yield distinguishing image features. To overcome this issue, we develop a new approach that combines a text-based spine rec...
Conference Paper
Full-text available
The emerging cloud gaming service has been growing rapidly, but not yet able to reach mobile customers due to many limitations, such as bandwidth and latency. We introduce a 3D image warping assisted real-time video coding method that can potentially meet all the requirements of mobile cloud gaming. The proposed video encoder selects a set of key f...
Article
Full-text available
In mesh-based peer-to-peer (P2P) streaming systems, each video sequence is divided into segments, which are then streamed from multiple senders to a receiver. The receiver needs to coordinate the senders by specifying a transmission schedule for each of them. We consider the problem of scheduling segment transmission in P2P streaming systems, where...
Article
Long network latency negatively impacts the perfor- mance of online games, and thus mechanisms are needed to mit- igate its effects in order to provide a high-quality gaming experi- ence. In this paper, we propose an indirect relay system (IRS) to forward game-state updates over detour paths in order to reduce theround-triptime(RTT)amongplayers.Wef...
Article
Full-text available
Peer-to-peer (P2P) systems generate a major fraction of the current Internet traffic, and they significantly increase the load on ISP networks and the cost of running and connecting customer networks (e.g., universities and companies) to the Internet. To mitigate these negative impacts, many previous works in the literature have proposed caching of...
Conference Paper
Virtual worlds, such as Second Life, are computer-simulated spaces divided into multiple regions, in which each user controls an avatar to perform actions (such as run and fly) in order to interact with other users. Second Life incurs diverse traffic patterns in different regions and with different actions. Hence, we propose region- and action-awar...
Conference Paper
Full-text available
Retrieving information about books on a bookshelf by snapping a photo of book spines with a mobile device is very useful for bookstores, libraries, offices, and homes. In this paper, we develop a new mobile augmented reality system for book spine recognition. Our system achieves very low recognition delays, around 1 second, to support real-time aug...
Conference Paper
This paper addresses the problem of disseminating multiple live videos to mobile users by using a hybrid cellular and ad hoc network. Specifically, we develop techniques to optimize the overall quality of video delivery by: (a) exploiting the flexibility of layered videos for in-network adaptation to reduce the gap between video coding rate and net...
Article
We study the scalable video broadcasting problem in mobile TV broadcast networks, where each TV channel is encoded into a scalable video stream with multiple layers, and several TV channels are concurrently broadcast over a shared air medium to many mobile devices with heterogeneous resources. Our goal is to encapsulate and broadcast video streams...
Conference Paper
Full-text available
Although network traces of virtual worlds are valuable to ISPs (Internet service providers), virtual world software developers, and research communities, they do not exist in the public domain. In this work, we implement a complete testbed to efficiently collect and analyze network traces from a popular virtual world: Second Life. We use the testbe...
Article
Full-text available
We present a general framework for optimizing the quality of video streaming in wireless networks that are composed of multiple wireless stations. The framework is general because: (i) it can be applied to different wireless networks, such as IEEE 802.11e WLAN and IEEE 802.16 WiMAX, (ii) it can employ different objective functions for the optimizat...
Article
Many mobile TV standards dictate using energy saving schemes to increase the viewing time on mobile devices, since mobile receivers are battery powered. The most common scheme for saving energy is to make the base station broadcast the video data of a TV channel in bursts with a bit-rate much higher than the encoding rate of the video stream, which...
Article
We address the problem of broadcasting multiple video streams over a broadcast network to many mobile devices, so that: (i) streaming quality of mobile devices is maximized, (ii) energy consumption of mobile devices is minimized, and (iii) goodput in the network is maximized. We consider two types of broadcast networks: closed-loop networks, in whi...
Conference Paper
Full-text available
In a multihomed video streaming system, a video sequence is simultaneously transmitted over multiple access networks to a client. In this paper, we formulate the rate control and stream adaptation problems into a unified optimization problem, which determines the sending rates of individual networks, selects which video packets to transmit, and ass...
Conference Paper
Full-text available
We study the problem of improving the user perceived quality of online games in which multiple players form a game session and exchange game-state updates over an overlay network. We propose an Indirect Relay System (IRS) to forward game-state updates over detour paths in order to reduce the round-trip time (RTT) among players. The IRS system effic...
Conference Paper
Full-text available
We consider multihomed scalable video streaming, where videos are transmitted by a single server to multiple clients over heterogeneous access networks. The specific problem that we address is to determine which video packets to transmit over each network, in order to minimize a cost function of the expected video distortion at the clients. We pres...
Conference Paper
Full-text available
Manual generation of a book inventory is time-consuming and tedious, while deployment of barcode and radio-frequency identification (RFID) management systems is costly and affordable only to large institutions. In this paper, we design and implement a mobile book recognition system for conveniently generating an inventory of books by snapping photo...
Conference Paper
Full-text available
Increasingly more users use mobile devices to watch videos streamed over wireless networks, and they demand more content at better quality. For example, market forecasts reveal that mobile video streaming, such as mobile TV, will catch up with gaming and music, and become the most popular application on mobile devices. In this tutorial, we will pre...
Article
Full-text available
In peer-to-peer (P2P) systems, a receiving peer needs to be matched with multiple sending peers, because peers have limited capacity and reliability. We study the following peer-matching problem: given a set of potential senders for an object requested by a re- ceiver, find the subset of senders that will minimize the load on the backbone network a...
Article
Full-text available
Maintaining an accurate and up-to-date inventory of one's assets is a labor-intensive, tedious, and costly oper-ation. To ease this difficult but important task, we design and implement a mobile asset tracking system for automatically generating an inventory by snapping photos of the assets with a smartphone. Since smartphones are becoming ubiquito...
Article
Full-text available
Mobile TV broadcast networks have received significant attention from the industry and academia, as they have already been deployed in several countries around the world and their expected market potential is huge. In such networks, a base station broadcasts TV channels in bursts with bit rates much higher than the encoding bit rates of the videos....
Article
Full-text available
In mobile TV broadcast networks, the base station broadcasts TV channels in bursts such that mobile devices can receive a burst of traffic and then turn off their radio frequency circuits till the next burst in order to save energy. To achieve this energy saving without scarifying streaming quality, the base station must carefully construct the bur...
Article
Modern mobile devices have evolved into small computers that can render multimedia streaming content anywhere and anytime. These devices can extend the viewing time of users and provide more business opportunities for service providers. Mobile devices, however, make a challenging platform for providing high-quality multimedia services. The goal of...
Conference Paper
Full-text available
In peer-to-peer (P2P) mesh-based streaming systems, each video sequence is typically divided into segments, which are then streamed from multiple senders to a receiver. The receiver needs to coordinate the senders by specifying a transmission schedule for each of them. We consider the scheduling problem in both live and on-demand P2P streaming syst...
Conference Paper
Full-text available
We propose a general quality-power adaptation framework that controls the perceived video quality and the length of viewing time on battery-powered video receivers. The framework can be used for standalone video devices (e.g., DVD players and notebooks) as well as mobile receivers obtaining video signals from wireless networks (e.g., mobile TV and...
Article
Full-text available
We study the problem of broadcasting multiple variable bit rate scalable video streams from a base station to a large number of mobile receivers. Our objective is to maximize bandwidth utilization, energy saving and perceived quality of the transmitted videos. In practice, the aggregate bitrate of the video streams can be greater than the available...
Conference Paper
Full-text available
We consider the problem of broadcasting multiple variable-bit-rate (VBR) video streams from a base station to many mobile devices over a wireless network, so that: (i) perceived quality on mobile devices is maximized, (ii) bandwidth utilization is maximized, and (iii) energy consumption of mobile devices is minimized. We show that this problem is N...
Conference Paper
Full-text available
We study the problem of broadcasting video streams over a WMAN to many mobile devices. We propose to form a cooperative network among mobile devices that receive the same video stream, and share received video data over a WLAN. We analytically show that the proposed system outperforms current systems in terms of energy consumption and channel switc...
Conference Paper
Full-text available
Modern mobile devices, despite their small sizes, can run many multimedia applications that were only possible to stationary workstations. Mobile devices, however, have quite heterogeneous resources, which poses a challenge to mobile TV broadcast networks. We study the problem of broadcasting multi-layer video streams to mobile devices with heterog...
Conference Paper
Full-text available
Mobile TV networks have received significant attention from the industry and academia, as they have already been deployed in several countries and their expected market potential is huge. In such networks, a base station broadcasts TV channels in bursts with bit rates much higher than the encoding bit rates of the videos. This enables mobile receiv...
Conference Paper
Full-text available
We study the problem of broadcasting multiple scalable video streams to heterogeneous mobile devices, which have limited energy budgets. We show that scalable video streams should be broadcast in a different manner than nonscalable streams; otherwise energy of mobile devices could be wasted. We propose an efficient broadcast scheme for mobile TV ne...