Mobile and Wireless Networks:

Retrospective and Remaining

Challenges

Jie Wu

Department of Computer and Information Sciences

Temple University

Wireless and Mobile Networks

Dead-end or the Dawn of a New Ear? Not dead-end

Greatest Opportunities Ahead Theory

Mobility: model and applications Applications

Mobile video and mobile cloud

PSU

Mobility: Friend or Foe Routing capability

Foe in dense mode (MANETs)

Friend in sparse mode (DTNs)

Network capacity

Security

Sensor coverage

Information dissemination (mobile pub/sub)

Reducing uncertainty in reputation systems

ICCCN 2011 Panel

Graph Models for Dynamic Networks

Movement-Assisted Routing in DTNs

Store

Carry

Forward

Applications Node movement

Vehicular networks (VANETs) Social contact networks (SCNs)

Edge dynamic Wireless sensor networks (WSNs)

• duty cycle

Cognitive radio networks (CRNs)• primary users (PU) and secondary users (SU)

pu: {c}

su1: {1, 2} su2: {1, 2, c}

u v

ICCCN 2011 Panel

Connectivity

(u,v) - connectivity under time-space view

• All i, (u(i), v(i))

• Exist i, (u(i), v(i))

• Exist i, j, (u(i), v(j))

View(i) View(i+1) View(j)

View window Time

Space

u v

Evolving Graph and Extensions Time sequence: t1, t2, ..., tL

Gi = (Vi, Ei): subgraph in [ti, ti+ Δ]

Evolving graph: (V, E), where

(u,v) = {i | (u, v) є Ei} (i: label)

Weighted evolving graph

(u, v) = {(i, wi) | (u, v) є Ei}

where weight wi: bandwidth,

reliability, and latency

ICCCN 2011 Panel

Optimization Problems Optimization

Earliest-completion

Fastest

Minimum-hop

Maximum-bandwidth

Maximum-reliability

ICCCN 2011 Panel

Solution: Slicing and Virtualization

SlicingPartition G into G1, G2, …, Gi

Select the best among i solutions for Gi

VirtualizationEnlarge G to G’ through virtualizationSolve G’ which includes a solution for G

Mobile video…

Popularity of mobile devices Smartphones (Android and iPhone platforms) Netbooks and tablets

Popularity of mobile video From 2009 – 2014, mobile traffic is predicted to increase

39 times 66% of this traffic expected to be video by 2014

Key technologies and players WiMax. Clearwire/Sprint, Korean Telecom, and UQ/KDDI

(Japanese)

LTE. NTT, DoCoMo, Verizon, T-Mobile, AT&T, China Telecom-Unicom, and KDDI

Wireless at Temple University

Metropolitan WiMax deployment Joint project with Drexel University and City of

Philadelphia. Our goal: Provide wireless coverage for downtown Philadelphia. Various projects (later).

Research projects

Tourist applications using city-wide WiMax WiMax centric bodynet for telemedicine Content delivery network using WiMax WiMax mobile surveillance for law enforcement WiMax enhanced mobile urban sensing

Wireless at Temple University Why WiMax?

Only choice within GENI. Need vendor support. Currently, only NEC.

Why Philadelphia? Digital Philadelphia. Gigabit city vision. Existing/proposed wireless infrastructure. e.g.

4.9 GHz Wimax video surveillance, 700 MHz LTE citywide overlay.