Heterogeneous Services And Architectures for Next-Generation Wireless Networks

Integrating Heterogeneous Wireless Technologies: A Cellular Aided Mobile Ad hoc

Network (CAMA)

And

Heterogeneous Services and Architecture for Next-Generation Wireless Networks

Simone Frattasi, Rasmus L. Olsen, Frank H.P. Fitzek, Ramjee Prasad (Aalborg University, Denmark)

Mauro De Sanctis – (University of Rome, “Tor Vergata”)

http://ctif.aau.dk/

Next Generation Networks (NGNs)

• 4G– MAGIC – extension of 3G cellular (cellular

structure with over 100 mbit/s rates) = linear 4G vision (Japan)

– Seamless service across multitude of wireless systems (non cellular) = concurrent 4G version

• Focus on personalized heterogeneous services

Wireless Personal Area Network

• Person to Person (P2P) vs. Person to Machine (P2M)

Services

• Resource Sharing– Efficiently organize resource consuption (e.g.

power, bandwidth)

Services (cont.)

• Synchronization– Global (per cell) vs Local (among related terminals) *

• Local is more flexible (choose local master on sign in to a common multicast)

• IP Datacasting– Data delivery without user awareness… ?

• Device to User (D2U) interaction• User to Device (U2D) interaction• Digital audio/video broadcasting/WPAN/WLAN/cellular (in off-peak

times)• Video clips, sports highlights, movie trailers, partial data delivery as

advertisement for data service

• Infrastructure – Context Manager (CM) and Service Manger (SM)

Integrating Heterogeneous Wireless Technologies: A Cellular Aided Mobile Ad

hoc Network (CAMA)

Bharat Bhargava, Xiaoxin Wu, Yi Lu, Weichao Wang

CAMA

• Use cellular network to improve ad hoc networks (like Signaling System 7 (SS7))– Offer QoS, and AAA (authentication,

authorization, and accounting) – why AAA ??– Manage the connections of Mobile Ad Hoc

Users (MTs)– Only control data goes through cellular base

stations, all user data is kept in ad hoc network

– Routing is not fixed – managed by CAMA

CAMA example

CAMA can aid in …

• Synchronization (offer clock sync)• Authentication (use cellular infrastructure or some other

mean like PKI)• Power saving (estimate transmit power since distance

between MTs is known)• Radio resource allocation (manage multiple channels

in an ad hoc network)• Broadcasting and multicasting (broadcast through

cellular base station ??? – contradicts their claim about all data in contained within ad hoc network)

• Finding cluster head in all clustered ad hock routing (aid in clustered ad hoc routing that was proposed by other research)

Feasibility analysis

• Ad hoc cell is small (because the transmit radius is small – so 1 cell can cover all of the ad hoc network)

• UMTS(3G) has sync and broadcast channels (some of which could be reserved for CAMA)

• Technology is available and cheap• Cellular providers try create more data

services

Previous work

• Heterogeneous integrated wireless networks (how ad hoc networks enhance cellular networks)

• Ad hoc routing with positioning – GPS, GPSR – route to peer closest to destination– VHR – position advertisement = large overhead– self positioning when GPS is not available– ABR - association beacon protocol

• Security– Open medium, dynamic topology changing, cooperative algorithms, lack

of centralized monitoring• Key distribution without a CA• Routing: digital signature to authenticate, hash chain to insure hop count

information• Architecture for intrusion detection

CAMA

• MT has GPS, and position is sent to CAMA through cellular base station (also cellular position service can be used) – a position of each MT is well known

• Routing done by CAMA or MT (the study assumes that CAMA will coordinate routes between src. and dest. – this also avoids periodic downlink position broadcasts, but slower since an MT might wait for CAMA to make its decision, also scale considerations

CAMA routing …

• Position information table per MT– d + (delta) d <= d (required link quality

threshold)

Routing cont…

N different routes are found for S to T : S-B-H-G-T and S-C-E-I-T

1: (B,C) and (B, C)

2: (F,H,E,D) and (H,E)

3: (G, N, I, K) and (G, I)

4: (L, T, J) and (T)

Packet end-to-end delay is used for ranking (transmission + back off + propagation)

Routing cont(2)…• Routing steps

– MT sends request to CAMA (resend in case there is no response)– CAMA replies with a complete route including all intermediate hops +

estimated transmission powers– Routing info is carried in the header of each packet

• Position update– MT sends its position update in a GPS aided positioning (if a change is

relatively small no update is needed)• Security (relates only to ad hoc network portion)

– CAMA agent can be a central security point for key distribution– Broadcast messages when intrusion is detected– If the GPS info is false, and there is no means to verify it – CAMA might

fail– DoS attacks

Security cont…

• False positioning information– Try to guess based on cellular position– Intrusion detection

• MTs can send a failed route message when the route did not work and CAMA can try to identify the malicious nodes

• Credit system

• Byzantine Behavior– Encrypt and sign header info– Report misbehaving nodes– Message hash verifications

• Anti Jamming– CAMA can detect the jamming condition and via MT reports and

make a decision to send client to different channel or maybe issue a jamming alert

Simulation results

• 100 MTs (1000m X 1000m)• Each MT moves with random direction and

random velocity between 0-3m/s (pedestrian speed)

• Ad hoc channel 1mbit/s• MSGPR is used for routing• AODV = ad hoc on-demand distance

vector routing• DSR = dynamic source routing protocol

Delivery Ratio

More Results…

More Results (2) ….

Result cont(3)…

Results cont(4)….

Conclusions

• Questions ??

• WiMax

• http://www.networkcomputing.com/showArticle.jhtml?articleID=191801683

• http://www.engadget.com/2006/08/07/caltrain-commuter-rail-pulls-wimax-at-79-mph/

• http://moment.cs.ucsb.edu/AODV/

• http://www.cs.cmu.edu/~dmaltz/dsr.html