Information Technology Reference
In-Depth Information
TaBLe 14.2
Comparison of V2R-Based and V2V-Based Vehicle Navigation Systems
V2R-Based Navigation
V2V-Based Navigation
Network architecture
Infrastructure-based
Infrastructure-free
Required equipment
Roadside units (sensors), Base
stations, Traffic information center,
Onboard units in vehicles
Onboard units in
vehicles
Backhaul connection
Required
No
Deployment cost
High
Low
Maintenance cost
High
Low
Transmission mode
One-hop transmission
Multi-hop relay
Transmission links
Vehicle-to-roadside links
Vehicle-to-vehicle links
Transmission reliability
High
Low
Network loading
Low
High
Computing mode
Centralized
Decentralized
Information management
structure
Hierarchical
Flat
Real-time traffic
information update
Periodic update
On-demand update
System robustness
Weak (single point of failure)
Robust
links of VANET to collect real-time traffic information. That is, real-time
traffic information is relayed from one vehicle to another using multi-hop
relay. Since all vehicles are mobile and move fast, a long multi-hop relay
link is vulnerable to link breaking. This means that the route query or
reply packet issued by the V2V-based vehicle navigation systems may be
lost during the packet relay process. Another important consideration is
that the network load of V2V-based systems is higher than that of V2R-
based systems because V2V-based systems employ multi-hop relay and
flooding to discover potential paths, while V2R-based systems simply
use one-hop communication to collect traffic information from passing
vehicles. Therefore, from the perspective of communication, V2V-based
systems are less reliable than V2R-based systems.
From the point of view of the computing mode, V2R-based systems
employ a centralized and hierarchical architecture. All real-time traffic
information is collected by roadside units (sensors), transmitted to BSs, and
then transmitted to TIC to generate routing information for guided vehicles.
However, since the TIC plays a vital role for the whole V2R-based system, it
becomes a single point of failure. For any disastrous events (such as fire or
network attack), the failure of the TIC will render the whole system useless.
Form the point of view of system robustness, V2V-based systems are better
than V2R-based systems.
