Incentives - Peer-to-Peer Computing: Applications, Architecture, Protocols, and Challenges - page 112

TABLE 5.3: A qualitative comparison of various wireless ad hoc data for-
warding approaches.

Proposed Incentive Implementation Security Major

Approach Scheme Di culty Required Drawback

Ileri et al. [Ileri et al., Payment Low High Energy-Based

Currency

2005]

Salem et al. [Salem et al.,
2006]

Payment High High Real Money

Marbach and Qiu [Mar-
bach and Qiu, 2005]

Payment High High Unlimited

Budget

Wang and Li [Wang and
Li, 2005]

Auction High High Communication

Buchegger and Le Reputation Low Low Trust

Boudec [Buchegger and

Boudec, 2005]

Felegyhazi et al. [Felegy-
hazi et al., 2006]

Utility Low Low Receiver's

Payoff

suggested are based on virtual currency. Specifically, each mobile user carries
some virtual currency in the form of a protected counter. Two different mech-
anisms are considered: producer-paid and consumer-paid. In the former, the
producer of information pays while the consumer pays in the latter. The price
P of a piece of information item (e.g., availability information about a parking
lot) is given by:

P = E−t− d
v

(5.42)

where E is the gross valuation of the information item, t is the time elapsed
since the information item is created, d is the distance to travel before the user
of the information can reach the relevant location (e.g., the parking space),
and v is the speed of the user. Simulation results under a simple situation
where there is only one consumer and two parking spaces indicate that the
proposed incentive mechanisms are effective.
Yeung and Kwok [Yeung and Kwok, 2006a] considered an interesting sce-
nario in wireless data access: a number of mobile clients are interested in a
set of data items kept at a common server. Each client independently sends
requests to inform the server of its desired data items and the server replies in
the broadcast channel. Yeung and Kwok investigated the energy consumption
characteristics in such a scenario.
Figure 5.18 depicts the system model for wireless data access. It consists
of a server and a set of clients, N . The clients are interested in a common
set of data items, D, which are kept at the server. To request a specific data
item, d a , client i is required to inform the server by sending an uplink request,
represented by q i (d a ). The server then replies with the content of the requested
data item, d a , in the common broadcast channel. This allows the data item to
be shared among different clients. As illustrated in Figure 5.18, both clients