the key challenges in maintaining QoS during handoffs. In today's networks UEs normally decide to which access network to connect which could lead to over-saturating the access network. In [15] authors have proposed a network driven QoS management and provisioning model where services trigger the reservation of resources without a direct involvement from the terminal. This model requires IMS which in the vast majority of the networks is not deployed and it is not expected to be in the next two to three years. Also, the radio network may lack some parameters that impact the handover decision, such as user preferences, the exact type of services active on the UE, and some operator policies pertaining to mobility between different radio technologies and putting an extra burden on network resources. 5 Security context includes: (a) agreed security algorithms between the UE and the serving network; (b) agreed/derived encryption and/or integrity protection keys and key identifiers; (c) security association related information like key lifetime, sequence number, count values, and SO on; and (d) the temporary identity issued by the serving network. E2E Network Architecture and Mobility Management The scheduling of EV-DO resources is primarily performed by the Proportional Fair packet scheduler. Though PF is good for data applications it might not be as efficient as needed for EPS. This could result in degradation of QoS when a user is transitioned from EPS to EV-DO. 11.8.3 Handover Latency The handover latency from one radio access to another should be no more than a few hundreds of milliseconds to ensure service seamlessness to users. The dual-radio which can simultaneously listen to two radio access technologies can expedite the handover process. However, it can suffer from perfor- mance issues due to RF co-existence, especially when the two different radio networks are deployed in neighboring or overlapping frequency bands. 11.8.4 Backhaul Backhaul will also be a concern if the targeted transmission media either is no