Eallae Kim

Decentralized DBA scheme based on power detection in TDM-PON

In this article, we propose a new decentralized hardware-based DBA scheme in TDM-PON. Of particular significance in the proposed scheme is that the bandwidth of the uplink data transmission is dynamically allocated to each ONU without the intervention of the OLT. In this way, software-based DBA processing can be eliminated in the OLT and ONUs, resulting in the simple, fast, and cost-effective operation of the DBA in TDM-PON. The performance of the proposed scheme was evaluated by performing a statistical analysis and numerical analysis of the average packet end-to-end delay. We confirmed the superior performance of the proposed scheme by comparing the results obtained for this technique with those of other EPONs.

A design of WDM/TDM-PON provisioning for future optical access network upgrade

In this paper, we propose a PON-based access network based on conventional TDM-PON architecture for the smooth, economical and effective transition to the future optical access network. We also propose a dynamic MAC protocol for wavelength channel and bandwidth allocation in the TDM-PON subscriber networks, which can provide enhanced network scalability and flexibility, and greater adaptability to the increasing number of subscribers in TDM-PON. In the proposed dynamic MAC protocol, several key functions are manifested, such as multiple wavelength channel utilization and dynamic allocation of multiple time-slots to a user depending on SLA between OLT and ONUs to meet QoS requirements. A dedicated control channel is used for delivering the request and status information between OLT and ONUs. We evaluate the performances of the proposed MAC protocol thru a statistical queuing analysis and numerical simulations. In addition, through simulations using various traffic models we verify the superior performance of the proposed approach by comparing it with conventional TDM-PONs.

Network architecture and fast handover scheme using mobility anchor for UMTS-WLAN interworking

UMTS-WLAN interworking has attracted many research efforts because each of UMTS and WLAN can maximize its capability in service provisioning. Through UMTS-WLAN internetworking, users can be offered the most suitable services according to service area and service provider can reduce network building and maintenance costs. In this paper, we propose a network architecture and fast handover scheme using Mobility Anchor (MA) for UMTS-WLAN interworking. MA is provided at the boundary between GGSN and PDG, under the 3GPP-proposed interworking reference model. Such MA can enable authentication and session establishment before L2 handover of the mobile node, so that seamless and fast vertical handover could be possible. Through computer simulation using OPNET for the performance measurement, the efficiency and validity of the proposed scheme has been examined.

Micromobility Management Enhancement for Fast Handover in HMIPv6-Based Real-Time Applications

In this paper, we propose a fast handoff algorithm for micromobility management enhancement in HMIPv6 networks, which eliminates the DAD procedure involved in the regular HMIPv6 in order to decrease handoff latency and increase the resource utilization efficiency. In the proposed scheme, the MAP is designed to guarantee the uniqueness of MNs interface identifier within a MAP domain as long as the MN moves in a MAP domain, so that the MN configures the new address without the DAD procedure resulting in the decreased handoff latency significantly. When the MN resides in a subnet, MIPv6 is used adaptively as a mobility management protocol, which is to reduce bandwidth waste from the IP packet header overhead of IP-in-IP tunneling from the regular HMIPv6. Thru various computer simulation results, we verified the superior performance of the proposed scheme by comparing with the results of other schemes, MIPv6 and HMIPv6.

Power Detection-based TDM-PON for a Novel Decentralized DBA

In this paper, we propose the power detection (PD)-based TDM-PON architecture, which is implemented for a hardware-based decentralized DBA (dynamic bandwidth allocation) among ONUs, without OLTs intervention to service. The proposed approach is characterized by a simple, fast and cost-effective operation on TDM-PON.

Chirp Reduction by SPM and XPM Cancellation in DWDM Optical Transmission Systems

Chirp cancellation method is proposed to reduce XPM effects in DWDM optical channels, which is executed by controlling the time delay and power of transmitted pulses. Simulation results verify the effectiveness of the proposed method.