An arrangement for providing IP mobility for a mobile station (MS) provides a care-of-address (COA) for routing data packets when the MS is away from home. In one embodiment, the arrangement includes support nodes, called gateway GPRS support nodes (GGSN) or serving GPRS gateway support nodes (SGSN), and a foreign agent (FA) having an IP address. In order to save IP addresses and radio resources, the FA is integrated into one of the support nodes (e.g., the SGSN), and the IP address of, or an IP address provided by the FA is also used as the MS COA.