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Chapter 4. MOBILE DEVICE CONNECTIVITY IN HOME NETWORKS. Section 4.1. Related Work. 4.1 Related Work. Two standardization forums : -> Decentralized home network, targeted for home entertainment applications 1.Home Audio Video interoperability (HAVi) Based on 1394
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Chapter 4 MOBILE DEVICE CONNECTIVITY IN HOME NETWORKS
Section 4.1 Related Work
4.1 Related Work Two standardization forums: ->Decentralized home network, targeted for home entertainment applications 1.Home Audio Video interoperability (HAVi) • Based on 1394 • Quality of Service (QoS). • Non-IP networking 2.Digital Living Network Alliance (DLNA) • Based on Universal-Plug-and-Play (UPnP) • Aims at creating interoperability guidelines based on existing standards.
4.1 Related Work • Open Services Gateway Initiative (OSGi)->Centralized • A framework that provides API and Java execution environment for building integrated home networks and adaptation functions between UPnP-controlled devices.
Section 4.2 Basic Home Use Cases
Section 4.3 Home Networking Challenges
4.3 Home Networking Challenges • Self-configuring • Buy-plug-and-play; incremental network deployment • Intuitive user interface 2. Self-healing • Radio interference • Cross-talk • Uneven wireless coverage …etc • Provide autoresume; easy-to-understand error explanation; easy-to-use debug tool 3. Security • Wired Equivalent Privacy (WEP) • Wi-Fi Protected Access (WPA) • HTTP Secure (HTTPS) • Bluetooth Security • UPnP security ...etc
4.3 Home Networking Challenges 4. Remote Access: same experience as at home • Round-trip delay ( GPRS vs. DSL vs. 802.11), • Cost ( Cellular vs. 802.11), • Capabilities of the devices (Desktop vs. Laptop vs. Mobile phone). 5. Dynamic IP addresses. 6. Mobile devices connecting • Users move in and out of range of local access points • Battery life • Screen size
Section 4.4 Architecture and Technologies for Local and Remote Home Connectinity
4.4.1 Overview of Home Connectivity Architecture Architecture: Centralized -> Decentralized • Automatic configuration and ease-of-use features cannot rely on a central element to hide technologies behind uniform APIs and middleware. Based on a layered approach. • Lower level : TCP/IP • Middle level: Control technologies ->UPnP , SLP • High level: Applications and media formats ensure interoperability and usability of the system.
4.4.2 Local Connectivity Infrastructure-based : • AP, switch, router, DHCP server • Connect : Fixed Ad hoc (Peer-to-Peer) based: • Connect : Opportunistic • Point-to-Point interactions between two devices
4.4.2 Local Connectivity Link-level technologies: 802.3 (Ethernet 10/100/1000 Mbps): • High data-rates, Low delays • Used for fixed home devices and mobile (No moving) • Requires cabling the home 802.11 a/b/g (Wi-Fi) • Allows for mobility within the home • Seamless support for Ethernet and IP • Unlicensed spectrum -> Signal fluctuation
4.4.2 Local Connectivity Bluetooth • Short-range, Low data-rates • Support for Ethernet encapsulation with BENP • Mainly used in ad hoc mode UltraWideBand (UWB; WiMedia) • Emerging wireless technology • Short-range, High-speed communication • Availability of the Wireless USB specification • Main issue: Delay the wide deployment in home networks due to lack of broad consensus in standardization
4.4.2 Local Connectivity IEEE 802.15.4 • Low data-rates (hundreds of Kbps), conserving power • Home automation applications involving sensors and actuators • Suitable for connecting a large number of devices HomePlug • High data-rates ( Tens of Mbps) • Plugged in regular electrical power sockets • Suitable for transmission of multimedia content
4.4.2 Local Connectivity IEEE 1394 (FireWire) • Serial bus wireline technology • Synchronous mode that can guarantee bandwidth. • Suitable for connecting several devices at the same time • Under pressure from USB 2.0 Near-Field Communications (NFC) • Two-way communication between two devices • Suitable for IP traffic exchange
4.4.2 Local Connectivity Mobile can use any of the above wireless or wireline link-level bearers to connect locally. Two problems to overcome: • To reduce power and conserve energy • To deal with frequent disconnections caused by signal fluctuations, interference, user mobility.
4.4.3 Remote Connectivity Three Challenges: 1. A broadband connection uses dynamic IP addresses that in many cases are not even public. ->Dynamic DNS 2. Traversing firewalls and NATs 3. Ensure the security of the remote connection • VPN (Virtual Private Network)
4.4.3 Remote Connectivity Several ways to implement remote access: 1. Proxy solution • Use distributed middleware (UPnP) • Authentication by TLS/ Secure Sockets Layer (SSL) 2. VPN-based solution • Requires VPN gateway at the Internet gateway and VPN client at the remote terminal