Self-Configuration and Administration of Wireless Grids - Cloud, Grid and High Performance Computing: Emerging Applications - page 264

Figure 3. Wireless Grid spanning multiple virtual organizations

RS and BS provide the naming service for
resource discovery across the AOs and VOs.
The notion of grid service (Foster et. al, 2001)
can be extended to the wireless grids. In such a
scenario, the RS can provide a naming service for
resource discovery based on service description
(Winoto et. al., 1999; Zhu et al, 2003, Sharmin et
al., 2006)) at the node level. Resource discovery
can be extended to a virtual organization where
a BS can provide a naming service for resource
discovery within various actual organizations.
Multiple BSs can coordinate to provide service
discovery across multiple VOs.
Each node maintains information about itself
and the AO it belongs to. The RS maintains infor-
mation about its AO such as the name and address
pairs for its nodes, number of nodes, name of its
AO, names of the VOs to which its organization
belongs and the associated base stations. The BS
maintains information about its VO, the names
of associated AOs, names and addresses of as-
sociated RSs, and also the names and addresses
of other BSs. Note that the root stations and the
base stations can be part of the existing cellular
and internet infrastructure; they can be configured
to handle communication for one or more grids.

In such a case, the grid owners pay a fee to the
internet and cellular service providers to handle
their specific communication requests.

• Messages: Messages are used for commu-
nication between the grid components and
are a mechanism for resource discovery.
Figure 4 shows the structure of a message.
It consists of a three-field header followed
by a payload section. The header fields are
explained in Table 2. The payload holds
the data from the message specific to each
Opcode. Table 3 lists the possible opcode
values.
• Message Behavior: Enter and leave mes-
sages are used by the grid components to
announce their entry or exit from the over-
all system. Discover messages are used to
discover the grid resources. Hello messag-
es are used to validate the existence of the
grid components.