This document discusses routing and transport issues for using Content-Centric Networking (CCN) in Vehicular Ad-Hoc Networks (VANETs). CCN is proposed as an attractive solution for VANETs due to its ability to handle dynamic topologies and provide location-based caching and delivery. However, challenges exist regarding integrating CCN with the IEEE 802.11p WAVE standard, efficient routing given vehicle mobility and intermittent connectivity, and providing reliable transport. The authors propose a Content-Centric Vehicular Networking (CCVN) architecture that uses counter-based forwarding to limit broadcast storms and provider tables for multi-hop content retrieval. Preliminary simulation results show CCVN can

1. Content Centric VANETs:
Routing and Transport issues
Marica Amadeo, Claudia Campolo and
Antonella Molinaro
Speaker Marica Amadeo
CCNxCon, September 12, 2012

2. Motivations
CCN in Vehicular Ad Hoc NETworks
CCN is an attractive solution for wireless networks with
dynamic topologies
Several design challenges need to be addressed
INTERNET
V2I
vehicle-to-infrastructure
communication vehicle-to-vehicle
(V2I) communication
(V2V)
V2V
Sensors

3. VANETs Features
Unique applications
Traditional Internet-­‐based applications + new applications
(safety/non-­‐safety) designed for the road environment
Vehicle mobility
Quickly changing network topologies and short V2V and V2I
connection lifetimes
Node capabilities
GPS, unlimited power and storage
Ad-­‐hoc defined protocol stack
WAVE platform (IEEE 802.11p + IEEE 1609)
3

4.
CCN in VANETs
Potential benefits
Zero configuration networking
Matching the nature of location-­‐relevant applications
Easy and effective in-­‐network caching
Service over sporadically connected links
INTEREST
CS
FORWARDING
DATA PIT ENGINE
PROVIDER FIB
CONSUMER

5.
CCN in VANETs
Main issues
Architectural Issues
CCN and WAVE deployment
Routing Issues
Broadcast channel, highly dynamic network topologies,
short-­‐lived and intermittent connectivity
Transport Issues
Reliability, Flow control, Congestion Control

6. CCN in VANETs:
Main Issues
Architectural Issues
CCN and WAVE deployment:
How to work with legacy protocols?
Routing Issues
Transport Issues

7. Our Architectural Vision
Content-­‐Centric Vehicular Networking (CCVN)
non-­‐safety data retrieval and dissemination
compliant with IEEE 802.11p
SAFETY NON-­‐SAFETY SAFETY NON-­‐SAFETY
APPLICATIONS APPLICATIONS APPLICATIONS APPLICATIONS
UDP TCP
WSMP WSMP CCVN
IPv6
LLC LLC
802.11p MAC 802.11p MAC
802.11p PHY 802.11p PHY
Legacy WAVE stack With CCVN

8. CCN in VANETs:
Main Issues
Architectural Issues
Routing Issues
Broadcast channel, highly dynamic network topologies,
short-­‐lived and intermittent connectivity:
How to limit broadcast storm?
How to efficiently forward Interest and Data packets?
Transport Issues

9. Routing and Forwarding in
CCVN
Counter-­‐based scheme over each Interest and Data forwarding to
counteract broadcast storm
Scalable content delivery
Provider discovery via (multi-­‐hop) Interest broadcasting
Providers stored in the Content Provider Table
(CPT)
Content delivery:
Consumers choose their provider according to a given
selection criterion
Path-­‐state information in Data and Interest packets
M. Amadeo, C. Campolo, A. Molinaro Content-centric networking: is that a solution for upcoming

10. CCN in VANETs:
Main Issues
Architectural Issues
Layer 3 Issues
Layer 4 Issues
Reliability: How to manage Interest retransmissions?
Flow control: How to control the Interest transmission
rate?
Congestion Control: How to achieve congestion
detection and avoidance?

11. Transport
in CCVN
One Interest per Data packet
Reliability
A Consumer retransmits the Interest if the Data is not received
within a retransmission timeout interval, which depends on the
estimated RTT
Interest transmission rate
Simple choice: One Interest per RTT
Congestion control not performed yet
M. Amadeo, C. Campolo, A. Molinaro Content-centric networking: is that a solution for upcoming

12.
Preliminary Evaluation
Simulation Scenario
Simulator: ns-­‐2 RSU
Urban area
1 RSU and 100 vehicles RSU
VanetMobiSim mobility 300 m
(20-­‐40km/h)
Content size: 500 kbytes 300 m

13. Results
Fraction of nodes able to receive at most a given amount of
bytes of the requested content
5 downloads 20 downloads

14. Results
Cumulative distribution function of the download time
5 downloads 20 downloads

15. Conclusions
Some references about CCN in ad hoc networks
M. Amadeo, A. Molinaro Content-­‐Centric Architecture for IEEE
802.11 MANETs NoF 2011.
M. Amadeo, A. Molinaro A Content-­‐Centric Architecture for Green
M. Amadeo, C. Campolo, A. Molinaro CRoWN: Content-­‐Centric Networking in
Next steps: Layer 4 issues
Interest flow control
Interest pipelining?
Congestion control
Explicit congestion notification?

16.
Thanks for your attention
Content Centric VANETs:
Routing and Transport issues
Marica Amadeo, Claudia Campolo, Antonella Molinaro
name.surname@unirc.it