We will review some of the major results in random graphs and some of the more challenging open problems. We will cover algorithmic and structural questions. We will touch on newer models, including those related to the WWW.

Random graphs

It is shown that, particularly for terrestrial cellular telephony, the interference-suppression feature of CDMA (code division multiple access) can result in a many-fold increase in capacity over analog and even over competing digital techniques. A single-cell system, such as a hubbed satellite network, is addressed, and the basic expression for capacity is developed. The corresponding expressions for a multiple-cell system are derived. and the distribution on the number of users supportable per cell is determined. It is concluded that properly augmented and power-controlled multiple-cell CDMA promises a quantum increase in current cellular capacity. >

On the capacity of a cellular CDMA system

The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

IoT security: Review, blockchain solutions, and open challenges

The problem of error control and concealment in video communication is becoming increasingly important because of the growing interest in video delivery over unreliable channels such as wireless networks and the Internet. This paper reviews the techniques that have been developed for error control and concealment. These techniques are described in three categories according to the roles that the encoder and decoder play in the underlying approaches. Forward error concealment includes methods that add redundancy at the source end to enhance error resilience of the coded bit streams. Error concealment by postprocessing refers to operations at the decoder to recover the damaged areas based on characteristics of image and video signals. Last, interactive error concealment covers techniques that are dependent on a dialogue between the source and destination. Both current research activities and practice in international standards are covered.

/pdf/error-control-and-concealment-for-video-communication-a-3tm7c48xjc.pdf

Error control and concealment for video communication: a review

Advances in ubiquitous sensing and computing technologies, combined with the well developed theories in cognitive science, present major opportunities for the future Internet. We argue that the future Internet should be a usercentric and context-aware communication network, which goes far beyond today’s host-centric and store-forward Internet. In this article we propose to explicitly introduce the end-user’s context information into the future Internet framework. We, therefore, define a new functional module called the User-Context Module, and describe its architecture and key design principles. We also present two User-Context Module applications to aid gaining an understanding of its operation and impacts.

The 2 nd International Conference on Ambient Systems, Networks and Technologies (ANT-2011) The User-Context Module: A New Perspective on Future Internet Design

This paper proposes various approaches to improve the robustness of the ITU-T Recommendation H.263 video coder for operation in a fast fading mobile radio communications environment. Combined source and channel coding is used to selectively protect error sensitive bits in the encoded video bitstream. This works together with space and time diversity. Finally at the receiver, block replacement of erroneous and unrecoverable blocks ensures that the system can operate at channel SNRs of about 10 dB.

Robust H.263 portable video coding

A new packet CDMA network protocol that employs power-controlled transmissions is proposed and analysed. Three types of codes are used, namely base codes as pilot signals, mobile codes for communication purposes, and common codes for registration or location updating. The performance of such a network is analysed for both fading and non-fading channels.

Performance of a Power-Controlled Packet-Switched CDMA Network

In this paper, We propose a Q-learning-based routing scheme embedded with a power-control method to minimize the overall network delay performance. Various problems of applying reinforcement learning method in Mobile Ad hoc Networks (MANETs), such as optimization, the routing-loop problem and the convergence problem, are all addressed accordingly. A power-control scheme which makes use of the on-demand routing information to form an objective function are introduced in order to find an optimal power level that provides a suitable trade-off between transmission range and interference. The impact between power control and routing are also discussed in this paper. Simulations show that our method can achieve better performance under different load and mobility conditions.

An adaptive delay-based power control and routing scheme

To overcome scalability and control overhead problems existing in inter-domain multicast, DINloop (data-in-network loop) based multicast with MPLS is proposed. DINloop is a special logical path formed using MPLS label switched paths and it consists of multiple DIN nodes which are core routers that connect to each intra-domain. We use DINloop to manage inter-domain multicast group membership. Facilitated by the DINloop, multiple DIN nodes in the core network easily form a Steiner tree for multicast traffic. Furthermore, traffic for different multicast groups sharing the same path are aggregated through a label stack. Simulations demonstrate that DINloop-based multicast results in less message load needed to form the multicast structure. In addition, the routing table size in other core routers does not increase as the number of multicast group increases, and therefore routing scalability is improved. Finally, the inter-domain multicast delay in DINloop-based multicast is lower than that of a unidirectional tree.

Wai-Choong Wong

Papers

The 2 nd International Conference on Ambient Systems, Networks and Technologies (ANT-2011) The User-Context Module: A New Perspective on Future Internet Design

Robust H.263 portable video coding

Performance of a Power-Controlled Packet-Switched CDMA Network

An adaptive delay-based power control and routing scheme

A DINloop-based inter-domain multicast using MPLS