• Title/Summary/Keyword: IEEE 802.16.1a

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A Mobility Supporting MAC Protocol to Improve Handover Performance in IEEE 802.16j Multi-hop Relay Networks (IEEE 802.16j 멀티 홉 릴레이 네트워크에서의 핸드오버 성능 향상을 위한 이동성 지원 MAC 프로토콜)

  • Yang, Hyeon-Chae;Lee, Mee-Jeong
    • Journal of KIISE:Information Networking
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    • v.35 no.5
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    • pp.437-452
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    • 2008
  • IEEE 802.16j MR networks introduce RSs (Relay Stations) within the IEEE 802.16 system in order to enhance the data throughput and extend the coverage. However, the current standardization defines that the BS (Base Station) controls MS's (Mobile Station's) handover, not only it induces the large signaling overhead but also handover latency could increase. In this paper, we propose a handover protocol in the MR networks where the high capability RSs that can process the MS's control functions are deployed. First, we classify the handover scenarios for the MR networks with the high capability RSs. Then, we define the MAC handover procedure, corresponding MAC management messages and the transmission routes for the proposed messages so that an 802.16e MS can perform seamless handover without noticing it is attached to an MR network. The simulation results show that the proposed handover protocol not only reduces the MAC management message overhead transferred through the wireless links compared to IEEE 802.16j/D1, which is the current standard for MR networks, but also performs the rapider and more secure MS handover than IEEE 802.16e and IEEE 802.16j/D1.

Modification to Traffic Indication Method for IEEE 802.16 Sleep Mode Operation (IEEE 802.16 시스템의 슬립모드 동작을 위한 트래픽 인디케이션 방식의 개선)

  • Kim, Beom-Joon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.8 no.6
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    • pp.823-829
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    • 2013
  • IEEE 802.16 standard specifies the broadband wireless access (BWA) system including sleep mode to minimize the power consumption by a mobile station (MS). This paper outlines the overall operation of sleep mode and proposes a method to improve the power saving efficiency of the IEEE 802.16 sleep mode. The proposed method not only decreases the number of bytes that a MS in sleep mode needs to receive during listening interval but allows to indicate a control-specific operation such as periodic ranging.

Security Architecture and Authentication Protocol in Portable Internet (휴대인터넷의 보안 구조 및 인증 프로토콜)

  • Lee, Ji-Yong;Choo, Yeon-Seong;Ahn, Jeong-Cheol;Ryu, Dae-Hyeon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.872-875
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    • 2005
  • Portable Internet extended from wireless LAN has a large cell size, similar to a wireless mobile communication, and can provides the seamless service which offers middle-low speed mobility. IEEE 802.16e, the international standard of Portable Internet, uses PKMv2(Privacy Key Management) protocol for authorization and key exchange between a MSS(Mobile Subscriber Station) and a BS(Base Station). This paper first reviews and studies overall security architecture of TTA HPi standard and IEEE 802.16e which supports mobility based on WMAN(Wireless Metropolitan Area Network) standard(IEEE 802.16)

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RF Circuit Design for IEEE 802.11p Implementation (IEEE 802.11p 구현을 위한 RF 회로 설계)

  • Lee, Se-Yeun;Lee, Myung-Ho
    • Journal of Advanced Navigation Technology
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    • v.16 no.1
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    • pp.54-61
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    • 2012
  • The WAVE specification, which for the Next-Generation ITS environment is a common title: IEEE 802.11p and IEEE P1609 specifications. These days, there are many activities for researching WAVE specification by release of the IEEE 802.11p specification. The difference between high-speed vehicle environment and the indoor environment, the wireless communication channel mode is that much more severe. Thus, the wireless communication system design, temperature, noise, multipath fading and can degrade the performance of the system points should be fully considered matters of. In this paper, we showed WAVE wireless communication system which based on IEEE 802.11p PHY/MAC design process, and also showed solving process many implementation problems.

An Approach for Improving Mobile WiMAX Security - ROSMEX Architecture (안전한 모바일 와이맥스 네트워크를 위한 보안 구조 연구)

  • Shon, Tae-Shik;Koo, Bon-Hyun;Choi, Hyo-Hyun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.1
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    • pp.25-34
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    • 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.

A Design of SINR Measurement Unit for IEEE 802.16m (IEEE 802.16m 시스템의 SINR 측정기의 설계)

  • Kim, Jun-Woo;Park, Youn-Ok;Kim, Whan-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.12A
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    • pp.1097-1104
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    • 2010
  • This paper presents the signal-to-noise ratio (SNR) and signal-to-interference plus noise ratio (SINR) estimation based on A-Preamble of IEEE 802.16m IMT-Advanced WiMax system with simulation results. The downlink signal of IEEE 802.16m has two kinds of A-Preambles: the PA-Preamble and the SA-Preamble. This paper proposes the effective method of estimating SNR and SINR with A-Preambles, and also shows that this method can recognize the ICI(Inter-Carrier-Interference) occurrence due to doppler frequency. With the recognition of ICI, the mobile station can save the power by operating 1-tap equalizer in usual cases, and activating ICI mitigation module only when it perceives the ICI occurrence.

Time and Frequency Synchronization Algorithm for IEEE 802.16.1a Based Talk-Around Direct Communications (IEEE 802.16.1a 기반 단말간 직접통신을 위한 시간 및 주파수 동기화 알고리즘)

  • Bae, Jimin;Kim, Hyunsu;Chang, Sungcheol;Yoon, Chulsik;Choi, Jihoon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38A no.2
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    • pp.191-200
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    • 2013
  • In this paper, we propose a new estimation method of time offset, frequency offset, and signal to interference plus noise ratio (SINR) using the synchronization channel preamble to provide IEEE 802.16.1a based talk-around direct communications (TDC). The proposed scheme estimates the time offset and frequency offset both in the time domain and in the frequency domain considering the preamble structure. In addition, it improves the estimation accuracy by combining the estimated values in two domains taking into account TDC synchronization scenarios. Through numerical simulations in the TDC channel environments, the performance of the proposed algorithm is compared with those of existing techniques such as the time domain estimation and the frequency domain estimation.

An Efficient Femto-cell Scanning Scheme Using Network Assistance in IEEE 802.16e System (IEEE 802.16e 시스템에서 망 지원을 이용한 효율적인 펨토셀 스캐닝 방안)

  • Choi, Jae-In;Nam, Jin-Kyu;Seo, Won-Keyong;Cho, You-Ze
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.1B
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    • pp.21-28
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    • 2011
  • The femtocell is a miniaturized Base Station (BS) with low-cost and low-power using general broadband access network as backhaul. It is expected not only to improve indoor coverage but also to reduce a service charge. However, in IEEE 802,16e femtocells, when the Mobile Station (MS) scans neighbor BSs for handover, it takes a long time due to too many number of femto BSs. Also the size of the neighbor advertisement message that will be periodically sent by a serving BS is increased as the number of target femto BSs for scanning increases. In this paper, we proposed an efficient femtocell scanning scheme, using a triangulation mechanism and a femto BS monitoring scheme to reduce the number of scanning operations and the size of the neighbor advertisement messages. The proposed scheme can avoid wasting air resources and reduce scanning overheads by minimal scanning operation. The simulation results showed that the proposed scheme could improve scanning performance and avoid wasting air resources, compared with the conventional scheme of the IEEE 802.16e system.

A study on uplink QoS packet scheduler for VoIP service in IEEE 802.16 systems (IEEE 802.16 시스템에서 VoIP 서비스를 위한 역방향 링크 QoS 패킷 스케줄러에 대한 연구)

  • Jang, Jae-Shin;Lee, Jong-Hyup
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.1
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    • pp.145-152
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    • 2009
  • IEEE 802.16e standard, a kind of WMAN standard, was established to support data services with cheaper cost to mobile users than traditional mobile communications system and wireless LAN system can do. In this paper, we propose an uplink QoS packet-scheduler for VoIP service which can be installed in IEEE 802.16 system and evaluate its performance with NS-2 network simulator. The proposed QoS packet-scheduler consists of three procedures: determining scheduler interval, determining the amount of resource assignment, and deciding which mobile station the base station should serve first among multiple mobile stations. According to numerical results, the proposed QoS packet-scheduler can provide more increased system capacity by 220% than UGS service scheme does and by 25 % than ertPS service scheme does.

Wireless LAN System based on IEEE 802.1x EAP-TLS Authentication Mechanism (IEEE 802.1x EAP-TLS 인증 메커니즘 기반 Wireless LAN 시스템)

  • Hong, Seong-Pyo;Han, Seung-Jo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.9
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    • pp.1983-1989
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    • 2012
  • The IEEE 802.1x standard provides an architectural framework which can be used various authentication methods. But, IEEE 802.1x also has vulnerabilities about the DoS(Denial of Service), the session hijacking and the MiM(Man in the Middle) attack due to caused by structural of authentication protocol. In this paper, we propose a WLAN system which can offer safety communication by complement of IEEE 802.1x vulnerabilities. The WLAN system accomplishes mutual authentications between authentication servers, clients and the AP using PKI and prevents an illegal user from intervening in communication to disguise oneself as a client, the AP or authentication servers. Also, we guarantee the safety of the communication by the Dynamic WEP key distribution between clients and the AP.