# Analysis and Design of Functional Device for Vehicular Cloud Computing
## 5 Design of Relay-Assisted Scheme for Vehicular Application  
### Embedded Device Design  
The designed function module diagram of the vehicular device is illustrated in Figure 2 and based on Reference [38]. This embedded function device includes the following five modules: Receiving Unit, Collection Unit, Determining Unit, Sending Unit, and Storage Unit. Various Units work compatibly with one another. The Collection Unit, Determining Unit, and Storage Unit can be implemented by one or more processors. Additionally, the Receiving Unit and Sending Unit can be implemented by the antenna, filter, modulator-demodulator, and coder-decoder.  
In this device, the modules cooperate with one another. The functions of each part of this relay-assisted device are described as follows:  
Receiving Unit: Can be configured to receive relay-assisted setup requests from a source communication device.  
Collection Unit: Can be configured to respond to channel information collecting requests and to collect two-hop channel SNRs.  
Determining Unit: Can be configured to receive SNRs from all candidate relay-assisted communication devices and to determine if one or more relay-assisted communication devices are needed.  
Sending Unit: Can be configured to transfer a relay-assisted setup request to and from a source communication device, one or more relay-assisted communication devices, and a destination device.  
Storage Unit: Can be configured to save the acquired SNRs and relative tags of all candidate relay-assisted communication devices.  
This device can be placed in the control device of vehicular networks, and it is not limited to this placement. In summary, this device can be placed in any vehicle that is part of the vehicular networks. Source vehicle \(S\) can transfer messages to the destination vehicle \(D\) via relay-assisted vehicles \(R_{i}\). Figure 1 illustrates this vehicular networks scenario.  
Source vehicle \(S\) can send a relay setup request and/or channel information collection requests to the designed device. The Receiving Unit of this designed device receives the requests. Then, the Collection Unit of this designed device detects the channel information from where it is. Subsequently, the Determining Unit of this designed device achieves the SNRs, \(\gamma_{1}\) and \(\gamma_{2}\), for each candidate vehicle and selects one candidate vehicle as the relay-assisted vehicle on the basis of this information to communicate with destination vehicle \(D\). The \(\gamma_{1}\) and \(\gamma_{2}\) are obtained from the VC. We note that the Determining Unit can also be configured to be a Storage Unit. This way, the system can further reduce the amount of information requiring an exchange between the candidate communication devices and the designed device that can improve the network's efficiency. Finally, the Sending Unit sends the relay setup information mark, which has been designated to carry out the communication process to the source vehicle, selected relay vehicle, and destination vehicle. Storage Unit b must also save this information to reduce the processing time and to improve the network efficiency.  
To the best of my knowledge, some mentioned embodiments of this designed device can be implemented by partially or fully using hardware and/or firmware. Therefore, this device can be widely used in vehicular networks in the future.