Tae-Whan Yoo

A Hierarchical Weighted Round Robin EPON DBA Scheme and Its Comparison with Cyclic Water-Filling Algorithm

A H-WRR (hierarchical weighted round-robin) EPON (Ethernet passive optical network) DBA (dynamic bandwidth allocation) algorithm is devised and investigated. WRR table entries having reports are scanned to generate the gate which is limited to the token size of the entry. LLEDs (logical link IDs) are grouped into classes and maximum delay control is provided per class and minimum idle state polling rate is configurable for each ONT (optical network terminal). The schemes bandwidth allocation behavior and delay performance are shown through VHDL simulation with highly random self- similar traffic and comparison is made with previous CWF (cyclic water-filling) DBA (Kim et al., 2005). We conclude that in general, WRR DBA outperforms cyclic DBA and the H-WRR DBA scheme provides very low delay and high throughput.

Efficient authenticated key agreement protocol for dynamic groups

Group key management presents a fundamental challenge in secure dynamic group communications. In this paper, we propose an efficient group authenticated key agreement protocol (EGAKA), which is designed to be fully distributed and fault-tolerant, provides efficient dynamic group membership management, mutual authentication among group members and is secure against both passive and active attacks. The features of EGAKA are as follows: Firstly, EGAKA can be built on any general two-party key exchange protocol without relying on a particular one. EGAKA achieves scalability and robustness in heterogenous environments by allowing members to use any available two-party protocol in common and deliberately designed fault-tolerant mechanism in dynamic membership management. Secondly, EGAKA provides extremely efficient member join services in terms of both communication and computation costs which are constant to the group size. This is a very useful property in the scenarios with frequent member addition.

The Implementation of the Link Security Module in an EPON Access Network

In this paper, the link security module developed by draft standard of IEEE 802.1AE in order to protect all frames from a listening or attacking of a malicious user at an EPON link. And it applied at an EPON OLT (optical line terminal)/ONU (optical network unit) and is provided a link security about the maximum 64 ONUs. It also used a 128 bits GCM-AES (Galois/counter mode-advanced encryption standard) of an authenticated encryption mode that was mandatory-to-implement crypto- algorithm in draft standard. So, link security module can provide the user data confidentiality and frame data integrity, and data origin authenticity to subscribers, and support a link security at the maximum 2 Gbps EPON using the parallel CTR-AES (counter-AES) in the GCM-AES

Design and Implementation of an EPON Master Bridge Function in an ASIC

An EPON(Ethernet Passive Optical Network) master, slave chipset was developed. In EPON, LLID(Logical Link ID) value in the Ethernet frame’s preamble is used to make the PON look like a point-topoint links seen from the OLT(Optical Line Termination) and ONUs. This paper describes the functions and implementation of an EPON bridge in the master chip which performs bridge function for the upper network port and many lower PON logical ports differentiated by LLID. This bridge also has VLAN(Virtual LAN)-LLID mapping function to make the PON appear as many VLANs seen from the network port. It is also possible to define many VLANs for each ONU. It also has multicast pruning function through which only registered multicast traffic is sent downstream to destined ONUs.

Network slicing architecture for 5G network

3GPP SA2 [6] is currently developing 5G network architecture with a code name of NextGen Network. Network slicing architecture is the key issue to change the network paradigm into a new unforeseen stage of a programmable softwarized network. Although there have been many related research projects, NextGen network will be the first large-scale commercial network that adopts the network softwarization. This paper will discuss the current design issues on network slicing architecture, and proposes a new top-down approach and NextGen RRC architecture to resolve the current problems.

Mobility level management for 5G network

5G network architecture is actively discussed in 3GPP SA2 [6] where management of mobility level is one of the key study items. Mobility management of the previous generation defines seamless mobility for the always connected service without packet loss. 5G network designed to support the level of mobility based on the UE demands. This paper explains the mobility level management framework for the connected mode. Different levels of HO are defined. Architecture and control procedure to support multiple HO level is described.

An Improved Cyclic Water-Filling EPON DBA Providing Priority Scheduling and Faster Allocation Time

A cyclic water-filling EPON (Ethernet passive optical network) DBA(dynamic bandwidth allocation) algorithm and its implementation in an ASIC are described with future improvements. Every cycle, short static gates are generated to collect reports and dynamic gates are generated according to the reports collected in previous cycle. In each cycle, unit length is additively allocated to the ONUs in a cyclic fashion until all the requests are satisfied or no resource is left. Four parallel engines are used to process the requests. As improvements, priority will be considered, and the processing burden will be evenly distributed to the 4 parallel engines in any case.

Architectural design of an ONU controller for the ATM-PON

In this paper, we describe the functional architecture of an ATM-PON (passive optical network) system, which can provide diverse services via existing copper lines using very high bit rate digital subscriber line (VDSL) technology. Our PON-ONU (optical network unit) system accommodates POTS/ISDN/VDSL interfaces and integrates heterogeneous traffic using ATM technology. We realize core functions in customized ASICs.