MOBILE DEVICE CONNECTIVITY

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Chapter 4

• MOBILE DEVICE CONNECTIVITY
• IN HOME NETWORKS

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Section 4.1

• Related Work

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4.1 Related Work

• Two standardization forums -gtDecentralized 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.

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4.1 Related Work

• Open Services Gateway Initiative
  (OSGi)-gtCentralized
• A framework that provides API and Java execution
  environment for building integrated home networks
  and adaptation functions between UPnP-controlled
  devices.

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Section 4.2

• Basic Home Use Cases

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4.2 Basic Home Use Cases
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4.2 Basic Home Use Cases
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Section 4.3

• Home Networking Challenges

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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

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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

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Section 4.4

• Architecture and Technologies for Local and
  Remote Home Connectinity

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4.4.1 Overview of Home Connectivity Architecture

• Architecture Centralized -gt 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 -gtUPnP , SLP
• High level Applications and media formats ensure
  interoperability and usability of the system.

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4.4.2 Local Connectivity
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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

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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 -gt Signal fluctuation

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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

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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

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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

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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.

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4.4.3 Remote Connectivity

• Three Challenges
• 1. A broadband connection uses dynamic IP
  addresses that in many cases are not even public.
• -gtDynamic DNS
• 2. Traversing firewalls and NATs
• 3. Ensure the security of the remote connection
• VPN (Virtual Private Network)

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4.4.3 Remote Connectivity
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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