• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.1
• /
• pp.25-34
• /
• 2010

The IEEE 802.16-2004 standard has a security sub-layer in the MAC layer called, Privacy Key Management (PKM). However, several researches have been published to address the security vulnerabilities of IEEE 802.16-2004. After the IEEE 802.16-2004 standard, a new advanced and revised standard was released as the IEEE 802.16e-2005 amendment which is foundation of Mobile WiMAX network supporting handoffs and roaming capabilities. PKMv2 in Mobile WiMAX includes EAP authentication, AES-based authenticated encryption, and CMAC or HMAC message protection. However, Mobile WiMAX still has a problem of security architecture such as a disclosure of security context in network entry, a lack of secure communication in network domain, and a necessity of efficient handover supporting mutual authentication because Mobile WiMAX security has mainly concentrated on between SS and BS communication. Based on the investigation results, we propose a novel mobile WiMAX security architecture, called RObust and Secure MobilE WiMAX (ROSMEX), to prevent the new security vulnerabilities.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.1
• /
• pp.51-56
• /
• 2011

WiBro network technologies developed mainly by Korea are one of very promising 4G technologies. WiBro has been standardized as international standard called Mobile WiMAX, and has been deployed in many countries. Emergency Services in WiBro networks are infrastructure services and will be very essential to induce subscribers from other types of networks. This paper proposes a network architecture for supporting emergency services for WiBro mobile VoIP networks. The proposed architecture is based on WMF's architecture for international compatibilities, and reflects national considerations on interfacing PSAP for domestic compatibilities.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38B no.5
• /
• pp.355-367
• /
• 2013

In the Policy and Charging Control(PCC) architecture of the 3GPP and WiMAX forum, the Policy and Charging Rule Function(PCRF) controls and configures the policies of quality of services(QoS) and accounting to a Policy and Charging Rule Enforcement Function(PCEF). In this paper, we categorize the errors into three types that include a disconnection with peer entity, a delayed or no response and a response with failure result, and propose a scheme to automatically synchronize the data between the PCRF and the PCEF for each type of error. Also, we conduct a quantitative analysis to see how much it can help to maintain the cell capacity of the mobile VoIP service in a WiBro network, which is implemented in Korea according to the standards of WiMAX. We can see that our proposed scheme improves the performances of PCC by preventing the waste of radio resources, the overload of systems, the memory leakage of servers, the system shutdown, and so on. We have validated the scheme by implementation, and reflected it in WiMAX standard documents.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.2
• /
• pp.329-334
• /
• 2010

Due to the advancement of mobile wireless networks, various LBS's (Location Based Service) with the knowledge of mobile station's current position are emerging. Providing LBS is very essential feature in Mobile WiMAX networks such as WiBro networks for their competitiveness. To this end, WiMAX Forum has established recently the network architecture and protocols for providing LBS and they are included in the Network working group's release 1.5 documents. Though there have been many research efforts on location determination in Wibro networks, none of them addresses the location determination mechanism complying to Forum's recent LBS standards. This paper proposes an enhanced TDOA-RTD combined location determination mechanism, which complies to the Forum's LBS architecture.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.10a
• /
• pp.414-416
• /
• 2010

WiBro network technologies developed mainly by Korea are one of very promising 4G technologies. WiBro has been standardized as international standard called Mobile WiMAX, and has been deployed in many countries. Emergency Services are infrastructural servicesa and very essential to induce subscribers from other types of networks. This paper propose a network architecture for supporting emergency services for mobile VoIP services in WiBro networks. The proposed architecture is based on WMF's architecture for internationa compatibilities, and reflects national considerations on interfacing PSAP for domestic compatibilities.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.3
• /
• pp.103-110
• /
• 2010

This paper addressed the implementation of the systematic performance analysis of Quality of Service (QoS) by using OPNET simulator in the interworking architecture of IEEE 802.16e (mobile WiMAX) and IEEE 802.11e (WLAN) wireless network. Four simulation cases were provided in OPNET simulator and a voice traffic was simulated with various performance metrics, such as Mean Opinion Score (MOS), end-to-end delay and packet transmission ratio. Based on the simulation results, the MOS value presented better in WiMAX to WiMAX case compared to others in both static and mobility case. Meanwhile, end-to-end delay was not greatly affected by mobility in four cases. However, mobility was affected much in MOS value and packet transmission ratio in WLAN to WLAN case than in others.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.10 no.2
• /
• pp.97-102
• /
• 2010

In this paper, an area-efficient FFT processor is proposed for IEEE 802.16e mobile WiMax systems. The proposed scalable FFT processor can support the variable length of 128, 512, 1024 and 2048. By reducing the required number of non-trivial multipliers with mixed-radix (MR) and multi-path delay commutator (MDC) architecture, the complexity of the proposed FFT processor is dramatically decreased without sacrificing system throughput. The proposed FFT processor was designed in hardware description language (HDL) and synthesized to gate-level circuits using 0.18um CMOS standard cell library. With the proposed architecture, the gate count for the processor is 46K and the size of memory is 64Kbits, which are reduced by 16% and 27%, respectively, compared with those of the 4-channel radix-2 MDC (R2MDC) FFT processor.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.2
• /
• pp.363-371
• /
• 2013

This paper describes a multi-standard LDPC decoder which supports 19 block lengths(576~2304) and 6 code rates(1/2, 2/3A, 2/3B, 3/4A, 3/4B, 5/6) of IEEE 802.16e mobile WiMAX standard and 3 block lengths(648, 1296, 1944) and 4 code rates(1/2, 2/3, 3/4, 5/6) of IEEE 802.11n WLAN standard. To minimize hardware complexity, it adopts a block-serial (partially parallel) architecture based on the layered decoding scheme. A DFU(decoding function unit) based on sign-magnitude arithmetic is used for hardware reduction. The designed LDPC decoder is verified by FPGA implementation, and synthesized with a 0.13-${\mu}m$ CMOS cell library. It has 312,000 gates and 70,000 bits RAM. The estimated throughput is about 79~210 Mbps at 100 MHz@1.8v.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.11 no.3
• /
• pp.270-276
• /
• 2018

This paper presents a low area 256-point pipelined FFT architecture, especially for IEEE 802.16a WiMAX systems. Radix-24 algorithm and single-path delay feedback (SDF) architecture are adopted in the design to reduce the complexity of twiddle factor multiplication. A new cascade canonical signed digit (CSD) complex multipliers are proposed for twiddle factor multiplication, which has lower area and less power consumption than conventional complex multipliers composed of 4 multipliers and 2 adders. Also, the proposed cascade CSD multipliers can remove look-up table for storing coefficient of twiddle factors. In hardware implementation with Cyclone 10LP FPGA, it is shown that the proposed FFT design method achieves about 62% reduction in gate count and 64% memory reduction compared with the previous schemes.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.6
• /
• pp.15-23
• /
• 2016

In this paper we presented 4G security models in an open environment. 4G networks have still more security holes and open issues for expert to notice. In here. we show that a number of new security threats to cause unexpected service interruption and disclosure of information will be possible in 4G due mainly to the fact that 4G is an IP-based, heterogeneous network. it tells about the security issues and vulnerabilities present in the above 4G standards.. we try to present several architectures behind 4G infrastructure for example WiMAX and 3GPP LTE architecture. Finally, we point to potential areas for future vulnerabilities and evaluate areas in 4G security which warrant attention. When you make a big dada program, If you use this network architecture then you can improve your learning speed.