Extending the DLNA-based Multimedia Sharing System to P2P Network on OSGi Frameworks

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1 Extending the DLNA-based Multimedia Sharing System to P2P Network on OSGi Frameworks 1,2 Chin-Feng Lai, 3 Min Chen, 4 Athanasios V. Vasilakos, 1,2 Yueh-Min Huang 1 Dept. of Engineering Science, National Cheng Kung University, Taiwan (cinfon@ieee.org,huang@mail.ncku.edu.tw) 2 Dept. of Applied Geoinformatics, Chia Nan University of Pharmacy & Science, Taiwan (cinfon@mail.chna.edu.tw) 3 School of Comp Sci & Technology, Huazhong University of Science and Technology, China (minchen@ieee.org) 4 Dept. of Comp & Telecomm. Eng, University of Western Macedonia, Greece (vasilako@ath.forthnet.gr) Abstract Multimedia video sharing has been developed rapidly over the past years. P2P multimedia sharing mechanisms for P2P network such as PPLive, PPStream, Joost, have been used popularly. However, if Content Server and Client in the home network have to transmit via P2P sharing, P2P network must be adopted, thus it is unable to increase the network transmission speed through this intranet connection. Although there are DLNA, HAVi, and Jini protocols in the home network to share multimedia files, it cannot access P2P network due to the limitation of home network framework. Therefore, this paper extends the DLNA-based multimedia sharing system to P2P network on OSGi frameworks, so that users can access multimedia resource on P2P Network via DLNA, and P2P network users can apply P2P network mechanism in OSGI bundle to access shared DLNA multimedia resource in the home network. Index Terms DLNA, p2p network, multimedia sharing. I. INTRODUCTION With development of home multimedia service technology, more and more multimedia become available to every corner of home through home network sharing. For example, once built into DVD player, DVD multimedia content can be viewed from any computer at home through home network [1-4]. The technology has led to rapid development of multimedia, thus more devices can be added to home network to share files, and more multimedia file contents can be accessible by home network sharing. As sharable file types and devices increase, home network development will inevitably break the limitation of intranet. The traditional multimedia video sharing mechanisms can only share multimedia video in the home network, which reduces the usage options. In order for all providers to join the sharing network more easily, while not being limited to home network, many studies attempted to extend Digital Living Network Alliance (DLNA) mechanism sharing from home network to the decentralized P2P network [5]. However, P2P network has no related sharing mechanism to access these multimedia information converted from home network [6-8]. To improve the video sharing mechanism, this study proposed DLNA-based Multimedia Sharing System for OSGI framework with Extension to P2P Network. This framework consists of two main parts: (1) for the decentralized P2P network, a multimedia sharing method is proposed based on Open Service Gateway Initiative (OSGi) framework, including registration, update, safety and dynamic video quality adjustment mechanisms, (2) for home network, based on the standard DLNA video sharing mechanism, multimedia sharing mechanisms of home network and the decentralized P2P network are combined, and Home Content Server Adapter that includes P2P bundle and DLAN bundle is used to provide sharing mechanism to share the media content information between WLAN and DLNA [10-13], so that DLNA Content in the home network can be obtained from the decentralized P2P network. Thus, DLNA Player in the home network can also acquire Content in the P2P network. The remainder of this paper is organized as follows. Section 2 introduces the system framework and role of each server or converter in the whole network; Section 3 presents the mechanism corresponding to the proposed system to help improving system performance and safety, Section 4 evaluates the system performance, and test the framework; finally, Section 5 gives conclusions. II. SYSTEM ARCHITECTURE The system architecture is consisted of six main components: (1) Service Provider Server (SPS); (2) Home Content Service Adapter (HCSA); (3) P2P Server (PS); (4) P2P Client (PC); (5) DLNA Player (DP); (6) DLNA Server (DS), as shown in Figure 1. As seen in the architecture diagram, PS and PC can appear in any P2P network, so that any multimedia file can be shared throughout the network. To access DLNA multimedia resource in the home network, the home network service relies on Home Content Server Adapter to deal with client request. Furthermore, there is a SPS in the network, containing several home networks, a few PSs and some PCs. Home network is composed of a Home Content Server Adapter, several DPs and DSs. Detail of system framework component will be introduced in following sections. A. Architectural Components 1) Service Provider Server (SPS): SPS is the management core of the network framework, covering all HCSAs and PSs on the network, and maintaining all multimedia file information in all PSs and HCSAs. SPS faces all network servers, including client as well. However, its primary task is to keep database content updated in real-time, and provide the latest information to users. As for PC, multimedia file list and information can be acquired from SPS database, and used to build multimedia video streaming. As for DP, HCSA acquires

2 Fig. 3. Home Content Server Adapter OSGi Architecture Fig. 2. Fig. 1. System Architecture Service Provider Server OSGi Architecture multimedia file information of other HCSA and PS from SPS regularly, and update multimedia file list in DP of its home network regularly by UPnP Event. Thus, when DP requests service, it can target at corresponding PS or DS directly. Its OSGi framework is shown as follows: Information Service Bundle: it is the communication window for all servers with SPS, and carries out registration, update, and search in Extensible Markup Language (XML). These tasks are completed by accessing the database, thus, Database Operation Bundle is in charge of database access, and collaborates with Information Service Bundle. Database Operation Bundle: SPS must be accompanied with a robust database system, so that all clients can have the complete and real-time multimedia file information, thus, the database system should record all multimedia files and corresponding HCSA addresses or PS addresses. When PC or DP requests the multimedia file information of HCSA or PS from SPS, the file locations in WLAN are constructed via the same Server ID between Server List table and Content List table. Since the locations of files are in WLAN, PC and DP can access the multimedia content directly. 2) Home Content Server Adapter (HCSA): HCSA plays the role of communication window for the home network in multimedia file sharing. For home intranet, HCSA obtains survived DS s in the home network by M-Search, and acquires shared multimedia file information in each DS by UPnP Browse, then converts these messages from internal IP to external IP, and registers it s information to SPS for P2P network. When multimedia file is located somewhere at some home network, video streaming of such multimedia file should be acquired through HCSA. As for P2P network, HCSA regularly receives multimedia file information shared by P2P network from SPS, and simulates HCSA into a virtual DS in the home network. These file information are provided in DLNA sharing format to DP in the home network. To receive file, DP will skip HCSA, and receive multimedia file directly from the Content Server. To build a home network sharing platform, HCSA should communicate with DS s and DPs in the home network and connect SPS s and PCs in the P2P network. HCSA contains OSGi framework as follows: P2P Bundle is the manner by which HCSA registers to SPS, while DLNA Bundle is provided for home network PS s to register HCSA. Information Service Bundle is used to access databases of home network and P2P network. Multimedia file information and paths of all DS s in the home network are recorded in HCSA. As a result, when establishing streaming with client, HCSA can find corresponding DS quickly. From SPS perspective, when connection of each home network with external P2P network is started, it registers to SPS through HCSA. In other words, a HCSA represents the entire home network service for P2P network, when PC requests multimedia file of the home network, Client will connect HCSA directly. The advantage is that SPS can provide service to Client efficiently, and leave the remaining work to HCSA, reducing SPS-to-PC traffic and improving service quality. When playing video stream, effort is made to let all clients enjoy good quality service. Moreover, devices in the P2P network differ in network quality, thus, unlimited transmission mode in the home network is infeasible in the P2P network. In terms of database, HCSA is present in two database systems. One represents the entire P2P network, whose format and content are the same as SPS database. The approach of distributing same data to all HCSAs is to reduce SPS loading. The other database represents the whole home network. Therefore, in local network database, HCSA records all PS addresses in the home network. 3) P2P Server (PS): PS can be any node in the P2P network if users would like to share multimedia files to the others, when this node is connected to network, it can share multimedia file in PS to all users throughout the network automatically. To register local multimedia file information to SPS for client sharing, multimedia video files contained in PS are directly registered to SPS, without going to HCSA. As to client end, once obtaining multimedia file information and location from SPS, it builds video streaming with PS. To adapt to network

3 Fig. 4. Fig. 5. P2P Server OSGi Architecture P2P Client OSGi Architecture dynamics and expand the sharing scope of multimedia files, PS OSGi framework is shown as below: PS has four major Bundles. When PS is started, it executes Registry Bundle automatically. Information Service Bundle transmits multimedia file information shared in PS to SPS. When PS is requested to provide service to client, then streaming among client is built through Stream Service Bundle. 4) P2P Client (PC): The main function of PC is to provide multimedia file for users. When PC searches multimedia file needed in SPS directly, it can provide multimedia play service to user. Once client knows the address of multimedia file needed from SPS, file information can be provided by PS in the P2P network or HCSA at home. PC framework is as shown below: In the above figure, Information Service Bundle is used to communicate with SPS. Since users may need to search for multimedia file information through SPS, in video streaming process, it may collaborate with PS or HCSA to detect network connection quality. As client mainly plays video stream, it contains a Multimedia Player Bundle, while video service quality is tuned after PS or HCSA detects network connection quality. B. P2P/Home Network Streaming Many factors should be considered for streaming mechanism. To improve user service quality, it is necessary to reduce probability of building ineffective streams, and save bandwidth, so as to provide multimedia sharing service needed by multiple users. In actual environment, bandwidth limit in the P2P network and operation quantity of each server must be solved; effective use of bandwidth should be solved in dynamic quality mechanism. Another important issue is to lower operation quantity of each server. To build stream, corresponding multimedia file path has to be found first. Without HCSA database, the client in the P2P network must request SPS for service, and then SPS transmits database content to client in XML format. The client searches PS location and establishes streamlining accordingly. When a client is located in the home network, it requests HCSA for service, likewise, HCSA will pack database data content into XML file. After acceptance, the client may search multimedia file resource needed according to user preference. As seen in Figure 1, SPS only accepts service request from clients in the P2P network, and home network DC is handed over to HCSA to provide connection information. Thus, a P2P network database system is set on HCSA, since the client quantity may be large. If all clients request SPS for service, SPS flow will be inevitably too high. After distributing database, the client may request different servers for service according to different environments, so as to distribute operation quantity and flow. Another problem is that, the multimedia information that is received by client may not necessarily be the latest. Because after XML file is transferred to client, network may change during search until streaming is established. Therefore, function of updating multimedia information is added to user interface, so that the user can receive the latest multimedia information. In regard to streaming mechanism, there are two complex connection mechanisms: 1) streaming between PC in the P2P network and DS in the home network; 2) PS in the P2P network provides streaming service to DC in the home network. 1. PC in the P2P network and DS in the home network PC streaming service construction depends on multimedia file location, if multimedia file is located at PS in the P2P network, then streaming is directly built with this server. In another case, when multimedia file is located at some DS in a home network, streaming has to be built through HCSA. Figure 6 shows the process of establishing streaming between PC and DS. in the P2P network, streaming construction only needs PS approval, the process of seeking PS approval includes client certification and flow analysis. Only after all these processes are defined can PS start Socket to build connection with client. If multimedia file is located in the home network, it will request to establish streaming with PC through HCSA, certification process at this time is the same as in the P2P network. The only difference is that, after building stream, the streaming will direct to HCSA from DS first, and to PC from HCSA. One probable circumstance is that, due to path failure, streaming cannot be established sometime, when PC informs SPS multimedia file information of streaming failure through Information Service Bundle. This action is to feed back wrong information to multimedia information provider in order to reduce probability of streaming failure and network bandwidth. 2. PS in the P2P network provides streaming service to DC in the home network. In terms of DC, to access DS in the same home network, DLNA Protocol should be applied. To access multimedia file in the P2P network, file information should be acquired through HCSA before connecting this PS. The difference is that, when DP fails to access multimedia file in the P2P network, as DLNA does not define failure disposition method, DP only corrects after accessing file information of SPS following HCSA cycle. Figure 7 shows the process of establishing streaming between PS and DC.

4 Fig. 6. The Connect Flows of PC and DS Streaming Fig. 7. The Connect Flows of PS and DC Streaming III. PERFORMANCE EVALUATION This system literally was implemented on Taiwan advanced research & education network. In sharing network, this study adopted database access time and network access time as the evaluation indices, since by shortening access time, more users can be served, in other words, better service quality can be provided. Furthermore, the influence of client requests on database access for the above actions is shown in Figure 8. When the number of clients is increased, DS add and update the DC information with broadcasting in HCSA architecture; hence HCSA Search and HCSA Update spend more time to access the database on the server, as well as the difference of time spent in each action on database. Another important consideration is network use time; the importance of time to network access is easily understood because for shorter service time, more users can be served on the network. As shown in Figure 9, HCSA Search takes most time to access network, because HCSA broadcasts messages to the all DCs in a home network and receive the responses from all DCs at the same time. According to the result of

5 Fig. 8. Server Database Access Time Fig. 11. Client Request Acceptance Ratio V. ACKNOWLEDGMENTS Chin-Feng Lais research in this paper was supported by Sustainable Growth Project (S) (98WFA ) of Department of Engineering and Application Science, National Science Council (NSC), Taiwan. REFERENCES Fig. 9. Server Network Access Time transmitting a film in 24Mbps of bandwidth in Figure 10 and Figure 11, we are aware that the number of clients held in external network is less than that of home network. IV. CONCLUSIONS This study proposed a DLNA-based Multimedia Sharing System for OSGI framework with Extension to P2P Network, which can overcome the restriction of previous multimedia sharing on intranet, integrate P2P network, and employ related mechanism to help adapting to dynamic change of network, while improving user service quality. [1] Y.W. Ma, C.F. Lai, C.C. Hu, M.C. Chen and Y.M. Huang, RFID-based Seamless Multimedia Services for Smart Homes, International Journal of Internet Protocol Technology, vol. 4, no. 4, pp , Nov [2] M. Alam and N.R. Prasad, Convergence Transforms Digital Home: Techno-Economic Impact, Wireless Personal Communications, vol. 44, no. 1, pp , Jan [3] J.H. Chou, S.A. Weng and C.F. Chen, Action Patterns Probing for Dynamic Service Composition in the home network, Wireless Personal Communications, vol. 51, no. 1, pp , Oct [4] G.B.D. Freitas and C.A.C. Teixeira, Ubiquitous services in the home networks offered through digital TV, in Proc. Of ACM symposium on Applied Computing, Honolulu, Hawaii, 9-12 March, 2009, pp [5] N. Venkitaraman and R. Lillie, A P2P model for SIP based telecom services, in Proc. Consumer Communications and Networking Conference, Las Vegas, Jan , 2008, pp [6] M. Rahman, D. Braun and D. Bushmitch, A Framework to Access Networked Appliances in Wide Area Networks, in Proc. Of Consumer Communications and Networking Conference, Las Vegas, Jan. 3-6, 2005, pp [7] J. Kim, Y. Oh, H. Lee, E. Paik, and K. Park, Implementation of the DLNA Proxy System for Sharing Home Media Contents, IEEE Trans. Consumer Electron., vol. 53, no. 1, pp , Feb [8] K.D. Moon, Y.H. Lee, Y.S. Son, and C.K. Kim, Universal Home Network Middleware Guaranteeing Seamless Interoperability among the Heterogeneous Home Network Middleware, IEEE Trans. Consumer Electron., vol. 49, no. 3, pp , Aug [9] K.D. Moon, Y.H. Lee, C.E. Lee, and Y.S. Son, Design of a Universal Middleware Bridge for Device Interoperability in Heterogeneous Home Network Middleware, IEEE Trans. Consumer Electron., vol. 51, no. 1, pp , Feb [10] H.Y. Lee and J.W. Kim, An Approach for Content Sharing among UPnP Devices in Different Home Networks, IEEE Trans. Consumer Electron., vol. 53, no. 4, pp , Nov [11] N. VENKITARAMAN, Wide-Area Media Sharing with UPnP/DLNA, in Proc. Of Consumer Communications and Networking Conference, Las Vegas, Jan , 2008, pp [11] C.L. Hu, W.S. Liao and Y.J. Huang, Mobile Media Content Sharing in UPnP-Based Home Network Environment, Journal of Information Science and Engineering, vol. 24, no.6, pp , Nov Fig. 10. Server Transmit Bandwidth