plications. Launching a new application either shares an existing PDN Connection or creates a new parallel PDN Connection with its own IP address, effectively making the UE multi-interfaced. The host IP stack and the radio modem are typically tightly integrated. Split-UEs (see Section 2.6.2) have a clear separation of the host IP stack and the radio modem. They are sometimes even in physi- cally separate devices. Hence, a Split-UE is just like any IP enabled host equipped with a wireless radio networking technology. All applications typically share the same single PDN Connection. The Split-UE model is increasingly becoming the dominant design. The 3GPP Release-7 enhancements on the High Speed Packet Access (HSPA) radio technology and architectural enhancements aiming at a flatter network (e.g., direct tunnel- ing) have significantly reduced the gap between the cellular and fixed broadband access. Moreover, the 3GPP Release-8 Long Term Evolution (LTE) for both radio and core net- work evolution has brought cellular broadband access to and even beyond the mass market fixed broadband access - such as Digital Subscriber Line (DSL) - in terms of network latency and throughput. The increase in cellular broadband usability and the near flat rate billing models have had two notable outcomes: 1) consumers use cellular broadband in similar way to fixed access and 2) the cellular Internet service providers have experienced an exponential IP traffic growth. Heavy traffic growth poses investment pressures on radio access, backhaul and packet core capacity. Today 3GPP packet core network architecture and live network deployments tend to favor heavy IP traffic aggregation at a Gateway GPRS Support Node (GGSN) or Packet Data Network Gateway (PGW) into relatively few sites. The IP traffic packet for- warding capacity of these gateway nodes might not sustain the traffic growth. In addition, the increased capacity investment requirements can be hard to meet due to the declining average revenue per user. The issues discussed above h