Wireless Network Issues

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Wireless Network Issues

• Sridhar Machiraju

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• Goal Provide seamless connectivity.
• Service provided mobility across different
  access technologies.
• Related work Mobile IP.
• What is new Simultaneous presence of a more
  than one access networks a set that may also
  change rapidly.
• Drawback of mobile IP
• Inefficiency (triangle routing)
• No option to forward to a care-of-address based
  on source address (without having home agent
  figure it out).
• Requires a mobile host to have a fixed address!

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Mobility Servers
Server
IP1
Optimal Path
NAT
Mobility Server
IP2
N A T
Internal
MIP1
IP
MIP2
Mobile Host
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• What else do u gain with mobility as a service?
• IPv4 address scarcity.
• Who is not interested in making money?
• Other interesting issues/scenarios
• The HAs need to be near the servers an
  interesting dual to the caching service.
• What is the best way to compose the mobility and
  caching service to get the best QoS?
• Synchronization of split multimedia streams
  received on more than one interfaces.
• What are the interactions with other proxies
  transparent and non-transparent.
• How can wireless-WAN operators shed their load to
  wireless-LANs?

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Wireless access capacity sharing

• Shared 3G access networks
• Trend for 3G operators to share resources either
  by jointly owned access (e.g. form a trusted
  joint company-- opens up for virtual operators).
  Credit card
• or to use national cross-roaming agreements and
  cover different geographical areas.
• WLAN and 3G combined to increase hot-spot
  capacity -- multi-access networking
• WLAN may be owned by third party and
• Host multiple 3G operators

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• Resources shared/traded between WLAN and 3G
  networks
• Issues
• Applications (real-time multimedia) moved from 3G
  to WLAN require QoS in WLAN?
• Type of user devices and user behaviour (capacity
  needs and hand-over requirement)?
• A gain for operator to dynamically clearing 3G
  resources by moving traffic to WLAN in hot spots?
• Single point authentication -- reach the same
  subscriber database regardless off access type
  (based on AAA infrastructure)?

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• Issues
• Is there a business in providing the access
  services?
• WISP provides WLAN access for N operators
  (unlicensed)
• One of the N mobile operator opens up for (N-1)
  in a shared/confederated way (licensed spectra)
• Roles for the fixed ISPs (e.g. the home access)
• Mechanisms for trading access capacity
• Who provides the (global) mobility service?
• Probably the mobile operatorbut
• IP addresses a scarce resource for many mobile
  operators (even with IPv6)

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• Mobility Scenario Bay area commuters
• x million Connected people move every day from
  residential areas via public transportation/roads
  to office districts around the Bay
• Transitions from Cable/DSL(WLAN) - 3G - campus
  WLAN
• Some requires uninterrupted service when moving
  between networks -- interactive MM
• Some can tolerate interrupted flows
• Some require VPN support