Nam-Hoon Park

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In this paper, we evaluate handover (HO) performance when user equipment (UE) moves between femto cell and macro cell in long term evolution (LTE) systems. The focus is on the HO performance for inbound and outbound mobility which corresponds to handoff between the femtocell and the macro cell. Due to the severe signal-to-interference noise ratio (SINR)(More)
The femtocell access point of LTE-Advanced system, which can be deployed under macrocell coverage, was applied to the paper. The paper consists of two analyses which are the interference impact by the femtocell and the macrocell at a user equipment and the load impact to the control plane in evolved packet core network by X2 and S1 handover signaling(More)
As telematics and infotainment services are becoming more and more prevalent on the roadway, modern vehicles need to be equipped to support various wireless communication standards. The conventional ways for implementing those standards are dependent on their dedicated hardware chips, and thus in order to add a new standard or change an obsolete standard, a(More)
Femtocells are usually deployed in an indoor environment to provide in-building coverage enhancements. However, femtocells get to provide services for not only indoor users but also outdoor users in vicinity. Without the knowledge from the femtocell of whether the serviced users are located indoor or outdoor, the outdoor users are likely to experience low(More)
In this paper, we investigate the performance of IEEE802.16d random access protocol based on orthogonal codedivision-multiple-access and frequency-division-multiple-access in time division duplexing mode using equilibrium point analysis. The random access protocol of IEEE802.16d is similar to demand-assigned multiple access with piggyback, in which(More)
This paper deals with a call admission control method for hybrid mode femtocell base stations. Femtocell base station is a small scale base station which is used for home, office and apartment. On the hybrid access mode, the femtocell base station allows cell entrance for both member subscribers and non-member subscribers. Originally, the base station was(More)
In this paper, we investigate a queueing performance of an adaptive Type-I hybrid-Automatic Repeat reQuest(ARQ) scheme in a TDMA System over a non-stationary channel. In the system, we assume that an arriving message of variable size over a medium access control(MAC) layer consists of a number of unit information of fixed size. It is fragmented in MAC layer(More)