# Distance-Based Resource Allocation for Vehicle-to-Pedestrian Safety Communication
## 1 Introduction  
Vehicular communication has seen a recent shift in terms of technology with the introduction of the cellular V2X technology proposed by the 3 rd Generation Partnership Project (3 GPP). The 5 th Generation cellular technology has paved a way for the inclusion of the vehicles in the cellular domain [1]. Release 14 introduced the concept of V2X communication for the first time by including the air interfaces and core network technologies to support the V2X communication. Cellular V2X technology will not only resolve the data rate issues for onboard services but will also improve the safety communication by allowing two users in the vicinity of each other to have direct communication with each other. The device-to-device (D2D) communication (introduced earlier in Release 12 of the 3 GPP) allows any two cellular users (within a certain range) to share safety information with each other. The D2D communication is basically the driving force for the V2X communication with out-of-coverage and partial coverage scenarios, the D2D communication ensures the safety of the cellular users in remote and out-of-bound areas where the cellular coverage is low to none. Since, the inception of the concept of cellular-based V2X, there is a new room for research in the intelligent transportation system (ITS) area. A shift from the Wi-Fi-based dedicated short-range communication (DSRC) to the seamlessly connected vehicles in C-VTX, has been seen in the research community. A comprehensive survey on the vehicular technologies [2] has highlighted the various technologies along with their standardization bodies, use cases, security aspects, software defined vehicular networks (SDVN), and internet of vehicles (IoV) among other things. An area of particular interest is the radio resource management (RRM) for vehicular communication using cellular technology. The author in [3] has reviewed the challenges involved in the paradigm of radio resource management by an extensive survey of the objectives, techniques, and their achieved performances. According tothe survey V2X communication is still in its preliminary stage and requires an extensive research in areas of RRM, effective handoff mechanisms, and reliable channel signal information. The V2X technology is broadly categorized in V2V, V2I, V2P, and V2N scenarios. V2V scenario considers two vehicles in vicinity of each other to share safety information in order to avoid accidents or to alert the other vehicle about traffic jams etc. The V2I scenario is simply a vehicle communicating with the infrastructure. Like V2V, V2P scenario is also for safety communication between a vehicle and pedestrian. Whereas, V2N is a vehicle which is accessing the network for cloud-based services. V2V and V2I require ultra-reliability and high capacity, respectively. Other aspects of the V2X communication like vehicle-to-sensors (V2S), vehicle-to-grid (V2G), and vehicle-to-human (V2H) are studied in [4] as an emerging technology in current R&D. V2P being one of the most crucial scenarios for vulnerable road users (VRUs); i.e., users which are in close proximity of a moving vehicle and are prone to an accident. Pedestrians on the verge of crossing a road, a cyclist nearby or on the road, and pedestrians on a busy street all qualify as VRUs. A recent survey on VRUs in [5] shows the increasing number of fatalities in different countries. The author classifies the VRUs into categories such as cyclist, motorized two wheelers, and pedestrians. Furthermore, the author performs a case study for pre-crash scenarios under different technologies. While most of the research consider scenarios that include V2I and V2V users, we have aimed to present a roadside scenario, that specifically focus on the V2P links. In our scenario, vehicular user equipment (VUE) share resources with cellular user equipment (CUE). A VUE and CUE form a D2D pair when they are in certain range of each other. This pair is referred to as V2P. V2P which is similar to a V2V link is aimed for highly reliable safety communication.