Delivering Live Multimedia Streams to Mobile Hosts in a Wireless Internet with Multiple Content Aggregators

We consider the distribution of channels of live multimedia content (e.g., radio or TV broadcasts) via multiple content aggregators. In our work, an aggregator receives channels from content sources and redistributes them to a potentially large number of mobile hosts. Each aggregator can offer a channel in various configurations to cater for different wireless links, mobile hosts, and user preferences. As a result, a mobile host can generally choose from different configurations of the same channel offered by multiple alternative aggregators, which may be available through different interfaces (e.g., in a hotspot). A mobile host may need to handoff to another aggregator once it receives a channel. To prevent service disruption, a mobile host may for instance need to handoff to another aggregator when it leaves the subnets that make up its current aggregator�s service area (e.g., a hotspot or a cellular network).\ud In this paper, we present the design of a system that enables (multi-homed) mobile hosts to seamlessly handoff from one aggregator to another so that they can continue to receive a channel wherever they go. We concentrate on handoffs between aggregators as a result of a mobile host crossing a subnet boundary. As part of the system, we discuss a lightweight application-level protocol that enables mobile hosts to select the aggregator that provides the �best� configuration of a channel. The protocol comes into play when a mobile host begins to receive a channel and when it crosses a subnet boundary while receiving the channel. We show how our protocol can be implemented using the standard IETF session control and description protocols SIP and SDP. The implementation combines SIP and SDP�s offer-answer model in a novel way

A Mediation Framework for Mobile Web Service Provisioning

Web Services and mobile data services are the newest trends in information systems engineering in wired and wireless domains, respectively. Web Services have a broad range of service distributions while mobile phones have large and expanding user base. To address the confluence of Web Services and pervasive mobile devices and communication environments, a basic mobile Web Service provider was developed for smart phones. The performance of this Mobile Host was also analyzed in detail. Further analysis of the Mobile Host to provide proper QoS and to check Mobile Host's feasibility in the P2P networks, identified the necessity of a mediation framework. The paper describes the research conducted with the Mobile Host, identifies the tasks of the mediation framework and then discusses the feasible realization details of such a mobile Web Services mediation framework.Comment: Proceedings of 2006 Middleware for Web Services (MWS 2006) Workshop @ 10th International IEEE EDOC Conference "The Enterprise Computing Conference", October 16, 2006, pp. 14-17. IEEE Computer Societ

Efficient Batch Update of Unique Identifiers in a Distributed Hash Table for Resources in a Mobile Host

Resources in a distributed system can be identified using identifiers based on random numbers. When using a distributed hash table to resolve such identifiers to network locations, the straightforward approach is to store the network location directly in the hash table entry associated with an identifier. When a mobile host contains a large number of resources, this requires that all of the associated hash table entries must be updated when its network address changes. We propose an alternative approach where we store a host identifier in the entry associated with a resource identifier and the actual network address of the host in a separate host entry. This can drastically reduce the time required for updating the distributed hash table when a mobile host changes its network address. We also investigate under which circumstances our approach should or should not be used. We evaluate and confirm the usefulness of our approach with experiments run on top of OpenDHT.Comment: To be presented at the 2010 International Workshop on Cloud Computing, Applications and Technologie

IPv6 Multihoming Support in the Mobile Internet

Fourth-generation mobile devices incorporate multiple interfaces with diverse access technologies. The current Mobile IPv6 protocol fails to support the enhanced fault tolerance capabilities that are enabled by the availability of multiple interfaces. In particular, established MIPv6 communications cannot be preserved through outages affecting the home address. In this article, we describe an architecture for IPv6 mobile host multihoming that enables transport layer survivability through multiple failure modes. The proposed approach relies on the cooperation between the MIPv6 and the SHIM6 protocols.Publicad

Establishing Peer-to-Peer Distributed File Sharing System With Mobile Host

Viimase kümne aasta jooksul on mobiilsed seadmed nagu näiteks nutitelefonid, sülearvutid, pihuarvutid jne saanud lahutamatuks osaks igapäeva elust. See aga on tekitanud nõudluse võimsamate, kiiremate ja energiasäästlikumate seadmete järgi. Lisaks on iOSi ja Androidi operatsioonisüsteemide väljalaske tõttu suurenenud nii mobiilirakenduste arv kui ka keerukus. Sarnane areng on toimunud ka veebiteenuste valdkonnas ja nutitelefonides on ligi-pääs veebiteenustele muutunud elementaarseks. See aga on viinud järgmise sammuni – veebiteenuste pakkumine otse nutitelefonidest. See kontseptsioon pole uus ja seda on põh-jalikult uurinud S. N. Srirama, kes pakkus välja Mobile Host (Mobiilne Veebiteenuse Pak-kuja) lahenduse 2006. aastal, ning mida on C. Paniagua uuendanud Android OS’ile aastal 2012 kasutades REST arhitektuuri ja OSGi’t. P2P (Peer-to-Peer ehk partnervõrk) põhinevad programmid nagu näiteks failide jagamine ja sõnumite saatmine on tänapäeval arvutikasutajate seas laialdaselt levinud. Ar-vutid üle maailma on ühendatud omavahel ja jagavad ressursse selles süsteemis ilma keskse serverita. Iga arvuti selles võrgus on võrdne sel moel, et on võimeline ligi pääsema ja alla laadima ressursse teistest masinatest selles süsteemis. Töö kirjeldab põgusalt Mobile Hosti, P2P arhitektuuri, valitud P2P BitTorrenti pro-tokolli ja kuidas neid tehnoloogiaid kasutati P2P hajusa failide jagamise süsteemi loomi-seks. Uurimuse käigus arendati välja hajus failide jagamise süsteem Mobile Hosti lisana kasutades BitTorrenti protokollil põhinevat C++ keeles kirjutatud Libtorrenti teeki. Valmi-nud programm on võimeline looma torrent faili, avama ja laadima ning jagama vastavaid faile. Lisaks on võimalik muuta failide hoiustamise asukohta ja määrata mõningaid ses-siooni seadeid nagu näiteks alla ja üles laadimise kiirust piirata ning porti määrata. Failide jagamise teenust pakkuvate seadmete otsingu lihtsustamiseks seati üles Apache SOLR 4.2.0 veebiteenus mcrlabs.net serverisse millega suhtlus käib automaatselt.Mobile devices such as tablets, PDAs, mobile phones etc. have developed rapidly during last decade and become inseparable part of people’s everyday life. These devices are equipped with embedded sensors, camera, touchscreen, more memory, powerful processor, mobile 3G and 4G networks and Wi-Fi capability as well as efficient power consumption mechanisms. These improvements have led to mobile devices being able to perform tasks that usually personal computers are capable of. What is more due to release of Android OS and iOS applications for such mobile devices have increased as well as their complexity. Being online has become ubiquitous as Wi-Fi and mobile data networks are available in most of the places. For example over 45% of world’s population is covered by 3G mobile network [2]. Needlessly to say that makes using web services form mobile devices a com-mon thing. Such improvements lead to next generation of services which can be provided not only from dedicated servers but also from mobile phones. The concept of mobile web services provisioning is not new and has been in the ground for some time. Srirama et al. proposed the concept of Mobile Host [3] in 2006 where the mobile device acts as service provider. Mobile Host enables seamless integration of user specific services to the enterprise by following web service standards, also on the radio link and via resources constrained smart phones. Moreover Mobile Host fosters the new generation of ubiquitous and context-aware applications enabling the consumption of web services anywhere at any time from the handset. Mobile Host has been updated to latest technologies like for example REST archi-tecture which replaced SOAP so web services would be focused on systems resources. Early versions of Mobile Host were developed in PersonalJava and J2ME and meant for Symbian devices but as now the biggest share in smart phones market is held by Android then Mobile Host was upgraded for that platform by Paniagua [4] in 2012. Contribution of this thesis was to develop Peer-to-Peer (P2P) distributed file shar-ing system to Mobile Host for Android. This feature comes in handy when we talk about services that enables file sharing. As Mobile Host by its nature can join or leave network at any moment then accessing files that client is interested in becomes critical as file to be downloaded would be offered only by one provider as in regular client-server architecture. P2P distributed file sharing capability for Mobile Host provides users more reliable file sharing environment in distributed manner as files are downloaded as pieces from all the online peers who have pieces of desired file. What is more, small metadata torrent files are hosted by Mobile Hosts and published as a service. This setup assures the independency from other platforms and hosts

Adding Policy-based Control to Mobile Hosts Switching between Streaming Proxies

We add a simple policy-based control component to mobile hosts that enables them to control the continuous reception of live multimedia content (e.g. a TV broadcast) while they switch between different distributors of that content. Policy-based control provides a flexible means to automate the switching behavior of mobile hosts. The policies react to changes in the mobile host's environment (e.g. when a hotspot network appears) and determine when and how to invoke an earlier developed application-level protocol to discover the capabilities (e.g. supported encodings) of the content distributors and to execute the switches. The design of the control component is based on the IETF policy model, but extended and applied at the application-level instead of at the network-level. We implemented the system and deployed it in a small-scale test bed