Cellular networks, e.g., Universal Mobile Telecommunications System networks, will be based on the Internet Protocol (IP) to provide an efficient support for applications with bursty traffic characteristics, as, for example, issued by Web browsers or streaming applications. Such IP-based networks must include Quality of Service mechanisms to enable the usage of real-time applications, for example, mobile telephony. In wireless mobile networks this especially challenges handoff functions: handoffs should not lead to significant interruptions even though resource shortages after a handoff cannot be avoided completely.To overcome this problem, a simple and scalable handoff prioritization scheme called SiS-HoP is proposed. It dynamically reserves resources for handoff purposes. This way, SiS-HoP limits the number of sessions, which are interrupted in case of a handoff, to less than 1%. This is achieved without compromising the resource utilization in scenarios with many non-mobile terminals. In contrast to existing schemes, SiS-HoP is well-suited for future IP-based mobile networks with small cells where a high number of handoffs may occur during the lifetime of a session.