• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.105-108
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• 1999

In this paper, we define the high-speed router as a router, which can support aggregated ports over 25Gbps, and provide issues and trends in high-speed router design. We propose design considerations on IP packet forwarding, switching fabric, packet scheduling and buffer management, network resource reservation, and router operation and administration.

• Journal of information and communication convergence engineering
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• v.1 no.3
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• pp.123-128
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• 2003

This paper has addressed the implementation of the single rate Rate Adaptive Shaper(srRAS) described in RFC2963. This shaper has been proposed to use at the ingress of differentiated services networks providing Assured Forwarding Per Hop Behavior (AFPHB). srRAS is typically used in conjunction with single rate Three Color Marker(srTCM) described in RFC2697. srRAS itself is the tail-drop FIFO that is drained at a variable rate, and srTCM is the marker with metering function. G-srRAS is the same as srRAS except that RAS receives the green token state information from the downstream srTCM to avoid delaying a packet in RAS although there are sufficient tokens available to color the packet green. In this paper, we have addressed the algorithm and the architecture of srRAS, and the scheme to implement srRAS using VHDL(Very high-speed integrated circuit Hardware Description Language) and its related tools.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.4B
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• pp.281-290
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• 2002

In this paper, we propose an efficient packet forwarding method for an IP-based wireless Internet access network. Packets are forwarded along with a flow, that is a kind of connection-oriented connection and established before delivering packets. For this purpose, we also propose a flow resolution method and a modified IPv6 header for delivering packet in the wireless Internet access network. In addition, the method to support the mobility of mobile stations is explained, and the implementation issues are discussed. In order to estimate the performance of the proposed method, we analyzed the delay time to deliver packets in the wireless Internet access network. The numerical results show that the proposed method is very efficient, in the view point of delay.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.9 no.5
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• pp.23-30
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• 2009

This paper addresses the design of trTCM (Two Rate Three Color Marker) described in RFC2698. It has proposed for trTCM to be used in Differentiated Service network that provides AF PHB (Assured Forwarding Per Hop Behavior). trTCM is the marker with the metering function, and consists of the token updating function and the marking function. The token updating function uses the dual token bucket. The marking function compares the token values with the length of input packet and then marks the result into IP QoS field (ToS field). In this paper, we design trTCM function and then addresses the scheme to implement it using FPGA technology.

• ETRI Journal
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• v.32 no.2
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• pp.273-280
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• 2010

The overall channel capacity of a multihop wireless path drops progressively over each hop due to the cascading effect of noise and interference. Hence, without optimal rate adaptation, the video quality is expected to degrade significantly at any client located at a far-edge of an ad-hoc network. To overcome this limitation, decoding and forwarding (DF), which fully decodes codewords at each intermediate node, can be employed to provide the best video quality. However, complexity and memory usage for DF are significantly high. Consequently, we propose syndrome-based partial decoding (SPD). In the SPD framework an intermediate node partially decodes a codeword and relays the packet along with its syndromes if the packet is corrupted. We demonstrate the efficacy of the proposed scheme by simulations using actual 802.11b wireless traces. The trace-driven simulations show that the proposed SPD framework, which reduces the overall processing requirements of intermediate nodes, provides reasonably high goodput when compared to simple forwarding and less complexity and memory requirements when compared to DF.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.175-178
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• 2004

This paper describes a new IP address lookup algorithm using a binary search on multiple balanced trees stored in one memory. The proposed scheme has 3 different tables; a range table, a main table, and multiple sub-tables. The range table includes $2^8$ entries of 22 bits wide. Each of the main table and sub-table entries is composed of fields for a prefix, a prefix length, the number of sub-table entries, a sub-table pointer, and a forwarding RAM pointer. Binary searches are performed in the main table and the multiple sub-tables in sequence. Address lookups in our proposed scheme are achieved by memory access times of 11 in average, 1 in minimum, and 24 in maximum using 267 Kbytes of memory for 38.000 prefixes. Hence the forwarding table of the proposed scheme is stored into L2 cache, and the address lookup algorithm is implemented in software running on general purpose processor. Since the proposed scheme only depends on the number of prefixes not the length of prefixes, it is easily scaled to IPv6.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.3
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• pp.31-39
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• 2011

In this paper, we propose an evenly distributed mesh scheme to support services in mobile ad-hoc networks. Two strategies, the adaptive upgrading of forwarding nodes and the adaptive downgrading of forwarding nodes, are presented in the scheme. Our proposed scheme can support construction of better multicast mesh that can give higher packet delivery ratio with lower duplicate data as well as solve the problem of serious congestion especially when node mobility and data transmission rate are high in mobile ad-hoc networks. The performance evaluation is performed via simulation using OPNET.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.1
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• pp.35-40
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• 2013

The messages on mobile terminal may contain context information such as user's location, time and preference. This paper proposes message forwarding system based on user's context. The server stores the predefined target addresses which may be mobile phone number, web server address and email address. On request for message transmission, the server tries to find a target address matching a user's context. Thus, a sender transmits messages to a representative address without knowing various receiver's addresses and a receiver can retrieve classified messages according to subject/location.

• Journal of Information Processing Systems
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• v.13 no.3
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• pp.618-629
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• 2017

Mobile nodes can't always connect each other in DTNs (delay tolerant networks). Many DTN routing protocols that favor the "multi-hop forwarding" are proposed to solve these network problems. But they also lead to intolerant delivery cost so that designing a overhead-efficient routing protocol which is able to perform well in delivery ratio with lower delivery cost at the same time is valuable. Therefore, we utilize the small-world property and propose a new delivery metric called multi-probability to design our relay node selection principles that nodes with lower delivery predictability can also be selected to be the relay nodes if one of their history nodes has higher delivery predictability. So, we can find more potential relay nodes to reduce the forwarding overhead of successfully delivered messages through our proposed algorithm called HESnW. We also apply our new messages copies allocation scheme to optimize the routing performance. Comparing to existing routing algorithms, simulation results show that HESnW can reduce the delivery cost while it can also obtain a rather high delivery ratio.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.6
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• pp.2870-2888
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• 2017

Recent studies have shown that the flow table size of hardware SDN switch cannot match the number of concurrent flows. Combined SDN Forwarding Element (CFE), which comprises several software switches and a hardware switch, becomes an alternative approach to tackle this problem. Due to the limited capacity of software switch, the way to route concurrent flows in CFE can largely affect the maximum delay that a flow suffers at CFE. As delay-guarantee is a nontrivial task for network providers with the increasing number of delay-sensitive applications, we propose an analytical model of CFE to evaluate a rules placement solution first. Next, we formulate the problem of Rules Placement with delay guarantee in CFE (RPCFE), and present the genetic-based rules placement (GARP) algorithm to solve the RPCFE problem. Further, we validate the analytical model of CFE through simulations in NS-3 and compare the performance of GARP with three benchmark algorithms.