Since the western world, including the European Union, had made the handover of suspects to The Hague a strict precondition for economic aid and normal relations, Serbia had little choice but to co-operate.
The different network selection and handover schemes proposed in the literature can be classified into three approaches according to who is responsible for making the handover decision: the terminal, the network or by a cooperation between both of them.
DIHAT makes the handover decision when the difference in RSRP consistently exceeds the trigger threshold during the entire TTT window to avoid the ping-pong effect.
The standard hard handover algorithm is the default one used in the LTE system, which makes the handover decision based on two variables: handover margin (HOM) and TTT [28].
Additionally, some of the MICS commands enable the upper layer to ask the link layer about its status before making the handover decision, this is very crucial to support proactive, mobile-initiated handover.
The proposed DIHAT scheme makes the handover decision when the integrated difference in the RSRPs consistently exceeds the trigger threshold during the entire TTT window to avoid the ping-pong effect.
The CoMP set represents the stations for which the measured SIR is larger than ε×S I R 1s t, where ε is a scaling factor and S I R 1s t is the largest experienced SIR. This generates UE-specific clusters and allows fast cell-selection, making the handover process similar to a soft-handover but based on station updates in the CoMP set.
Furthermore, the DMHP makes the IP handover in flat architecture transparent to the upper layer protocols and thus securely preserves the active sessions.
The proposed scheme works based on the Elliptic Curve Cryptography (ECC) algorithm, which makes the computational cost of the handover process smaller compared to other handover schemes.
