• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.9 no.1
• /
• pp.76-87
• /
• 2005

In this paper, we propose a new profile, ROHC(RObust Header Compression) profile 7, for SCTP with ROHC for applying robust header compression SCTP, which is a transport layer protocol. The proposed new profile 7 adds a new field of 1 or 2 byte size on the existing SCTP packet header, which can make the SCTP stream to be diveded into acknowledgement stream and data stream. In addition, the classification of the stream can be used for recovering fault context. Consequently, in the case of using proposed ROHC-SCTP, it is possible to reduce the SCTP header overhead rate and also can be saved bandwidth.

• Journal of the Korea Society of Computer and Information
• /
• v.10 no.5 s.37
• /
• pp.187-198
• /
• 2005

In this paper, we propose the enhanced header compression scheme for the efficient data traffic transmission in Ipv6 networks. The bandwidth of wireless links and IP networks will probably be limited due to properties of the physical medium and regulatory limits on the use of frequencies for radio communications. That is major cause of user throughput reduction. Therefore, We discuss the IPHC(RFC2507) and ROHC(RFC3095) scheme. IPHC is simple header compression scheme and ROHC is enhanced header compression that have fast optimal recovery scheme. We have studied the enhanced header compression scheme in ROHC. We will show that indication of compression context values preventing from packet losses can provide the fast recovery of compression state. Computer simulations show that the proposed scheme has better performance than the previous one.

• The KIPS Transactions:PartC
• /
• v.15C no.5
• /
• pp.399-408
• /
• 2008

Mobile WiMAX provides wireless broadband services for data communication based on IP protocol. The limitation of physical bandwidth in the radio links may cause performance degradation in providing wireless broadband services in WIMAX. To enhance the efficiency of the radio link utilization, Payload Header Suppression (PHS) is defined as an optional header compression mechanism for mobile WiMAX. It has, however, a very limited compression capability since it has very restrictive compression fields. In this paper, hence, we assumed the application of Robust Header Compression (ROHC), a header compression scheme proposed for links characterized by high bit error ratios, long round-trip times (RTT), and scarce resource, to Mobile WiMAX, and studied its performance. Previous studies on ROHC performance merely focused on the impact of high bit error rate. However, bit error is virtually transparent to ROHC in the wireless systems like WiMAX, since the MAC provides the bit error checking function. In order to evaluate the performance of ROHC in the Mobile WiMAX environments, therefore, we evaluated the performance of ROHC with respect to the packet losses instead of bit error. We investigated the impact of the ROHC parameters that are recommended for the implementation in the ROHC and compared the performance of ROHC with PHS.

• The KIPS Transactions:PartC
• /
• v.16C no.1
• /
• pp.57-64
• /
• 2009

In order to efficiently provide IP based Wireless Broadband services in Mobile WiMAX, schemes for more efficiently utilizing a limited bandwidth in radio links are needed. Robust Header Compression (ROHC), a standard header compression scheme proposed by IETF, Bi-directional Optimistic (O) mode provides higher compression efficiency and robustness compared with Payload Header Suppression (PHS) which is an optional header compression scheme for mobile WiMAX [1, 2]. However, if consecutive packet losses occur because of a Shadow Region of Mobile WiMAX or bit errors, header decompression failure rate of the ROHC O mode increases due to inconsistency of the compression information between the Compressor and the Decompressor. Therefore, a complementary mechanism is needed. In this paper, we propose an approach for the dynamic adjustment of an optimistic parameter, which has an effect on both the compression efficiency and the robustness, for improving the performance of ROHC O mode. We also analyze the performance of the proposed approach using an OPNET simulator.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2014.11a
• /
• pp.187-189
• /
• 2014

패킷 네트워크에서 음성, 영상 트래픽이 IP, UDP, RTP 를 이용하여 전송 될 때 중복 헤더가 사용되어 통신의 비효율을 초래한다. 이를 방지 하기 위해 ROHC(Robust Header Compression)가 적용된다. 이는 인접 패킷 헤더 간의 차이 값이 규칙적으로 증가하는 영역은 그 차이 값만을 전송한다. 차이 값은 WLSB 인코딩 과정을 거쳐 전송이 되는데 인코팅 시 Sliding Window 값이 사용된다. Sliding Window 크기에 따라 헤더 압축률이 변하고 대역폭에도 영향을 미치게 된다. 본 논문에서는 효과적인 Sliding Window 값을 구하여 기존 ROHC 에 적용 하여 네트워크 통신의 효율성을 향상 시키고자 한다.

• Information and Communications Magazine
• /
• v.32 no.4
• /
• pp.16-22
• /
• 2015

유비쿼터스 정보 기술을 기반으로 다양한 업무 지원 기기간 네트워크를 형성하여 업무 처리를 지원하는 u-Office와, 지능화된 다양한 사물에 인터넷 연결성을 제공하여 지능적 서비스를 제공하는 Internet of Things(IoT)는 기하급수적으로 증가하는 다수의 객체간 통신을 수행하므로 네트워킹 자원의 최적화 기술이 필수로 뒷받침되어야 한다. 데이터 패킷의 오버헤드를 줄이고 통신 자원을 절약하기 위한 기술 연구는 다방면으로 진행되고 있으며, 특히 패킷의 오버헤드를 줄이고 통신 자원을 절약하는 패킷 헤더 압축 기술은 다양한 국제 표준이 개발되어 모바일 와이맥스(Mobile WiMAX), Long Term Evolution(LTE), IPv6 over Low power Wireless Personal Area Network(6LoWPAN) 등의 네트워크에 활용되고 있다. 본 고에서는 모바일 와이맥스, LTE, 6LoWPAN에서 각각 사용되는 패킷 헤더 압축 기술인 Payload Header Suppression(PHS), Robust Header Compression(ROHC), Header Compression(HC), Improved Header Compression(IPHC)의 개발 동향을 제시하고 각 기술의 특징을 비교 분석한다.

• Journal of IKEEE
• /
• v.5 no.1 s.8
• /
• pp.8-15
• /
• 2001

This paper remarks IETF based requirements for IP/UDP/RTP header compression issued in 3GPP2 All IP Ad Hoc Meeting and protocol stacks of the next generation mobile station. All IP Network, for real time application such as Voice over IP (VoIP) multimedia services based on 3GPP2 3G cdma2000. Frames for various protocols expected in the All IP network Mobile Station (MS) are explained with several figures including the bit-for-bit notation of header format based on IETF draft of Robust Header Compression Working Group (ROHC). Especially, this paper includes problems of IS-707 Radio Link Protocol (RLP) for header compression which will be expected to modify in All IP network MS's medium access layer to accommodate real time packet data service[1]. And also, since PPP has also many problems in header compression and mobility aspects in MS protocol stacks for 3G cdma2000 packet data network based on Mobile IP (PN-4286)[2], we introduce the problem of solution for header compression of PPP. Finally. we suggest the guidelines for All IP network MS header compression about expected protocol stacks, radio resource efficiency and performance.