A PROXY SERVER
INFRASTRUCTURE
FOR ADAPTIVE MOBILE APPLICATIONS
Jianwen Wang and Thomas Kunz | |
Systems and Computer Engineering | |
Carleton University | |
http://kunz-pc.sce.carleton.ca/ | |
tkunz@sce.carleton.ca |
Motivation: The “Mobile Warrior”
Typically, related work focuses on bandwidth variation | |||
Other resources are also constrained (memory, power, CPU capabilities) and may vary over time | |||
Majority of solutions: introduce proxy between client (application executing on mobile device) and server, proxy compresses and filters data stream | |||
sometimes, degree of compression depends on available bandwidth | |||
user mobility often not addressed/supported | |||
Some other solutions: | |||
view mobile purely as User Interface (WWW browsers, Teleporting, ....) | |||
statically partition client application between mobile and proxy | |||
dynamically partition client application between mobile and proxy | |||
partition directed by application (Rover, MaROS, ....) | |||
partition transparent to application (using mobile code toolkits) |
Generic
Architecture
(presented at AI ‘99)
Sample Application: MPEG Player
Goal: facilitate design, implementation and deployment of new and innovative PCS services (resource-intense, multi-medial) | ||||
emphasis on transparently overcoming resource limitations and variances in available resources (power, bandwidth, memory, CPU speed) | ||||
resource variations exist during executions as well as between executions (cellphone vs. PDAs vs. laptop) | ||||
explore mobile code as unifying framework to investigate resource tradeoffs | ||||
Open issues: | ||||
collecting link bandwidth | ||||
costs of migration/handoff | ||||
use of hysteresis similar to location mgmt in cellular networks | ||||
load balancing between client and proxy (under way) | ||||
include WinCE or Palms (necessitates new mobile code toolkit) | ||||
comparison to “traditional” approaches, active networks | ||||
scalability to provincial or country-wide deployment: simulation |