IN-VEHICLE COMMUNICATION APPARATUS AND BANDWIDTH RESTRICTION METHOD PERFORMED BY THIS APPARATUS

To effectively ensure high priority communication while reducing connection fees.SOLUTION: An in-vehicle communication apparatus according to an aspect of the disclosure comprises: an out-of-vehicle communication unit that wirelessly communicates with a wireless base station in a mobile communication system; an in-vehicle communication unit that communicates via Ethernet with a plurality of communication devices inside the vehicle; and a relay processing unit that relays an uplink packet received by the in-vehicle communication unit to the out-of-vehicle communication unit and relays a downlink packet received by the out-of-vehicle communication unit to the in-vehicle communication unit. The relay processing unit reduces a window size of a TCP header of the following second packet in response to detecting the congestion of the following first packet. First packet is a downlink packet defined to have a first priority. Second packet is an uplink packet defined to have a second priority that is of lower priority than the first priority.SELECTED DRAWING: Figure 1 【課題】 高優先度の通信を有効に確保しつつ、回線使用料を削減できるようにする。【解決手段】 本開示の一態様に係る車載通信装置は、移動通信システムの無線基地局と無線通信する車外通信部と、車内の複数の通信機器とイーサネット通信を行う車内通信部と、前記車内通信部が受信した上りパケットを前記車外通信部に中継し、前記車外通信部が受信した下りパケットを前記車内通信部に中継する中継処理部と、を備える。前記中継処理部は、下記の第１パケットの輻輳を検出した場合に、下記の第２パケットのＴＣＰヘッダのウインドウサイズを削減する。第１パケット：第１優先度と定義された下りパケット第２パケット：第１優先度よりも低い第２優先度と定義された上りパケット【選択図】 図１