Transcript Sleep Apnea - University of Minnesota

Proposed Research Topics
Spring 2003
Abed E. Lawabni & Prof. Ahmed H. Tewfik
{ lawabni, tewfik }@ ece.umn.edu
Road Map
 Radio Resource Management Scheme for WLAN.
 Dynamic Frequency Allocation.
 Wireless Link Aggregation (Routing-Flow Optimization).
 Load Balancing Algorithms.
 Data Replication Vs. Erasure codes.
Radio Resource Management Scheme for WLAN
Efficient and Robust Data Paths
 Providing an efficient data path between the
client and the remote storage device to
achieve:
• Low latency.
• High throughput.
• Supporting different applications.
Radio Resource Management Scheme for
WLAN
MetaData Manager
Switching Hub
Gigabit Backbone
IP Network
OSD
within a Region
OSD
OSD
IEEE 802.11 AP
IEEE 802.11 AP
OSD
Multimedia
Object
Where it should be associated ?
What type of traffic is going to be requested?
Text
Object
Web
Object
Radio Resource Management Scheme for WLAN
(continue)
 Analytical Modeling.
 { traffic type, distance effect, PER, # of competing
stations, etc.}
 An Empirical (Measurement-based) Simulation.
Data Replication
 When a decision to replicate is made , where is the replicated
object located?
 Main Challenge is that future demand is an unknown.
 Formulating the object replication & positioning problem as a
Stochastic network resource allocation problem.
 Different terms in the cost Function:



Cross-correlation between observed demand for the objects and that of
other objects with a known demand load & location history.
Delay in accessing the object based on multi-queue models.
Allowing various priorities to be assigned to objects.
Data Replication
 Selecting the best replica from a set of replicas.
• Network distance (hop counts, round-trip time, bandwidth)
• Device load in delivering the best object to the client.
• Different object types may also require different performance
metrics: Multimedia objects vs. text objects.
 Erasure-resilient system Vs. Replication system.
Quantitative Comparison:
•
•
Time to failure.
Storage & Bandwidth requirements.
Replication strategies for compound objects such as
MPEG-21 objects.
Thanks
 Prof. Ahmed H. Tewfik
[email protected]
EE/CSci Building, Room # 6–177
 Abed E. Lawabni
[email protected]
EE/CSci Building, Room # 6–120