# A Cooperative Communication Protocol for QoS Provisioning in IEEE 802.11p/Wave Vehicular Networks  
[PERSON]  
1 School of Software, Soongsil University, Dongjak-gu, Seoul 06978, Korea; [EMAIL_ADDRESS]  
[PERSON]  
2 Division of Electronics & Info-Communication Engineering at Yeungjin College, Buk-gu, Daegu 41527, Korea; [EMAIL_ADDRESS]  
[PERSON]  
3 Department of Mechatronics, Incheon National University, Yeonsu-gu, Incheon 22012, Korea  
Correspondence: [EMAIL_ADDRESS]; Tel. : +82-32-835-8688335-86835-  
transmission rate and a more extended communication range is required. Furthermore, the need for communication between the two vehicles has emerged. The American Society for Testing and Materials (ASTM), a DSRC specification task group, has decided to explore the next generation DSRC technology to meet the requirements of the ITS while preserving the advantages of the legacy DSRC [1]. As a result of reviewing various communication technologies, the ASTM pointed out the wireless local area network (LAN) technology which is widely used in daily life and has secured stability and marketability. Based on an IEEE 802.11a standard, the ASTM defines a new specification called IEEE 802.11p that satisfies poor power supply noise and in-vehicle communication environment [2]. The service-related standard for the ITS is defined by the IEEE vehicular technology society (VTS) as IEEE P1609. The IEEE 802.11p and IEEE P1609 standards described above are collectively called a wireless access in vehicular environments (WAVE) standard [3]. In the US, 75 MHz of spectrum in the 5.9 GHz frequency band has been allocated for DSRC applications. Other frequency bands have also been used for DSRC applications even before the 5.9 GHz band allocation. Table 1 shows a spectrum allocation for WAVE/DSRC applications. The IEEE 802.11p standard defines the MAC layer and PHY layer considering a vehicle communication environment in IEEE 802.11 which is a conventional wireless LAN standard. In the legacy IEEE 802.11 standard, an inter-node communication is possible after the completion of scanning, authentication, and association procedures. However, the IEEE 802.11p standard defines an outside context of BSS (OCB) for omitting these procedures and enabling communication. IEEE 1609 is a standard of the upper protocol layer of the WAVE standard and includes IEEE 1609.2, IEEE 1609.3, IEEE 1609.4, and IEEE 1609.12 [4; 5; 6; 7]. IEEE 1609.12 defines the provider service identification (PSID) allocations, IEEE 1609.2 defines security service related standard, and IEEE 1609.3 defines networking related wave short message protocol (WSMP). IEEE 1609.4 also describes multi-channel operations. IEEE 1609.4 divides a wireless channel into a control channel (CCH) and a service channel (SCH) and allocates different frequency channels to each channel and switching each channel periodically. WAVE can support a data rate up to 27 Mbps in vehicles with a speed of up to 200 km/h. In consideration of natures of a vehicle network, WAVE standard adopts a WAVE basic service set (WBSS) concept and has a different technical feature from the existing IEEE 802.11 standard [3]. The WAVE standard provides a multi-channel DSRC solution, and various services are being developed that use V2V and V2I communications based on this standard. These types of services include crash warning services, traffic information update, navigation update, and infotainment. The WAVE communication system provides not only communication between the OBU and RSU, but also communication between two OBUs. The OBU is mounted in the vehicle and provides services to the driver and the passenger. The RSU is installed on the roadside and provides with the function of connecting to the external network. Therefore, the OBU can be connected to the external network through the RSU. Many studies related to WAVE have been performed [8; 9; 10; 11; 12; 13; 14; 15; 16; 17].