Download MPLS Based Web Switching

PANEL DISCUSSION
WoWMoM 2002
ARUP ACHARYA
IBM T J WATSON RESEARCH CENTER
[email protected]
Conventional wisdom : Integration of WLAN and WWAN


Integrated WLAN and GPRS cards allow
 High-speed access indoors (802.11a supports 54Mbps)
 Wide-area connectivity via emerging wide-area data services (GPRS /
3G)
Ongoing research on seamless roaming between LAN/WAN
In-building WLAN
Wireless WAN
(3G / GPRS)
Multi-hop wireless LANs in metro areas




Emergence of high-speed 802.11a WLANs (108Mbps)
WLANs can operate a varying rates (1,2,..,11, ..,22, ..,54, 108)
Reception range decreases with rate
Given the above, we can think of a cellular-like
architecture for multi-hop wireless networks
 Start with a large cell; as nodes increase
split into (higher rate) smaller cells
 Connect to the Internet via multiple
wireless LAN hops
54
22
11
Ongoing research on multi-hop WLAN

Enhanced medium access control
(MAC) protocol for 802.11 that
increases system throughput by
supporting parallel transmissions
(MACA-P)
P
P
Q
Q
B
A

New WLAN card architecture to
support packet forwarding within the
card
 “wireless” router
(see paper in WoWMoM 2002)
Joint work with Archan Misra, IBM Research
B
A
MACA-P : basic idea

“Master” sender-receiver pair announces “schedule”
 “Waiting room”, DATA tx period, ACK tx period
 A neighboring node of master sender can transmit DATA in
parallel
 A neighbouring node of master receiver can receive in
parallel
P
Q
control
DATA tx ACK
gap
RTS
CTS
B
A
RTS
CTS
B
A
Q
P
Possible deployment scenarios

City-wide multi-hop fixed wireless LAN networks
 could be run by a service operator, civic government

Two-tier mesh networks
 First tier : access point for user
 Second tier : access points interconnected via a wireless
mesh
 Backhaul to the Internet from a few points in the second tier
mesh
Eases deployment and cost
Application

VoIP gaining strength in the Internet
 Enterprises switching to VoIP for new installations
 Internet service providers offering VoIP
 VoIP over DSL and Cable in trials

Can VoIP be extended over multi-hop metro wireless
networks?
 Initial source of revenue
 Start offering media rich services gradually
Location based
Build a data network to support voice [wlan / IP based approach]
Rather than extending a voice network to support data service