Abstract: Real-time and multimedia applications require an end-to-end QoS guarantee, and various types of applications require various QoS conditions. A DiffServ network should guarantee different QoS conditions for different types of communications. In this paper, the effect of traffic control in a DiffServ core network is experimentally evaluated using bursty traffic generated by an MMPP (Markov-Modulated Poisson Process) model. The situation to be simulated is that there are hundreds of conversational video streams that are delay-sensitive and hundreds of streaming videos that are loss-sensitive. If there are bandwidth-sharing queues such as those follow WFQ (Weighted Fair Queuing) in the core no-des and the two types of video traffic are assigned to two of the queues, the requirements of both types of traffic can be satisfied in a better way (a more efficient way) by assigning a larger weight to the queue for the conversational video. In our experiment, the optimum ratio of the weights was ap-proximately 1.3 when the traffic rates were the same. The optimum weight shares depend on the nature of the traffic, especially the burstiness.

Introduction to this research theme: Policy-based Networking

Currently no abstract is available.

Introduction to this research theme: Policy-based Networking

Abstract: Voiscape is a communication medium by which people can talk each other while moving within virtual sound space freely. By using a prototype of voiscape called VPIIQ (Voiscape Prototype II Q), the effect of difference of QoS caused by network policies was evaluated subjectively. The result showed unexpectedly that the percentage of correct answers was higher in the case in which QoS is lower in the localization test. In the sound localization tests, the percentage of correct answers was higher when subjects performed operations to move or to turn than not to do so. However, in the speaker recognition tests, opposite results were observed.

Introduction to this research theme: voiscape

Abstract: A method for scalable QoS guarantee, in which QoS requirements are signaled by using a protocol similar to RSVP or NSLP and are aggregated in backbones, has been developed and prototyped. The requirements are propagated to the policy server by using policy-based routing and a policy outsourcing protocol. The policy server estimates the amount of traffic and controls the bandwidth sharing among the queues (WFQs) of the backbone routers. The effect of core traffic control has been evaluated by using an L3-switch GS4000 and bursty traffic generated by the MMPP model. The results showed that, if there are many conversational video and streaming traffics, the QoS requirements of both types of traffic can be satisfied by relatively increasing the weight of the former than that of the latter in some cases.

Introduction to this research theme: Policy-based Networking

Abstract: We are developing a new voice communication medium called voiscape. Voiscape enables natural and seamless bi-directional voice communication by using sound to create a virtual sound room. In a sound room, people can feel others' direction and dis-tance expressed by spatial sounds with reverberations, and they can move freely by using a map of the room. Voiscape enables multi-voice-conversations. In a virtual market place that will be realized by voiscape, people can not only buy goods or information but also enjoy talking with merchants and people there. In this demo, a vois-cape prototype called VPII is used for realizing such an environ-ment. Unfortunately, because prerecorded voices are used in this demo, the participants cannot talk with merchants. However, the participants can talk each other with small end-to-end latency (less than 200 ms) and will feel the atmosphere of the virtual market place. Prerecorded people and merchants talk each other in English, Japanese and Chinese in parallel and with crossovers, and partici-pants can virtually walk among them and can selectively listen one voice or hear multiple voices at once.

Introduction to this research theme: voiscape

Abstract: A method for conference-room management for an auditory-virtual-space-based voice-communication medium called voiscape and a voice-communication system prototype called VPII, which used this method, were developed. With this method, conference rooms (called sound rooms) are managed through SIP and SIMPLE (a presence-related event-notification mechanism). A user can not only obtain a room list and enter (select) or exit from a room, but can also create, modify, or delete rooms by SIMPLE messaging. Rooms, users, and objects are managed by their "soft state"; i.e., they are deleted when a time out occurs. Users are informed of room membership, presence of a user, e.g., location and direction in the room, and presence of an object in the room by SIMPLE messaging, i.e., by SUBSCRIBE, NOIFY, and PUBLISH requests. To reduce the messaging overhead, the partial notification mechanism of SIMPLE is used in VPII.

Introduction to this research theme: voiscape

Abstract: We are developing a communication medium called voiscape, which enables taking to people while selecting persons to talk by moving in a virtual "sound room". In the second prototype of voiscape called VPII, the FIR Method is used for low-delay HRTF filtering, the sound room - the range of motion - is identified with the room in acoustical cal-culation, and early reflections by the sound room walls are simulated. The early reflections produce out-of-head sound lo-calization and sound distance expression. We also implemented motion-tracking and interpolation algorithms into the spatialization method. VPII enabled a voice communication environment, in which speaker identification is easy, multiple conversation-contexts can be created in a room, and motions of users and objects in a sound room are natural and causes only small noises.

Introduction to this research theme: voiscape

Abstract: An improved prototype of the "voiscape" voice communication medium has been developed and subjectively evaluated. Voiscape enables natural and seamless voice communication by using sound to create a virtual "sound room" in which people, who are represented by different sounds, can move freely. It features low-delay motion-tracking spatial audio with simulated early reflections that produce out-of-head sound localization and sound distance expression. It also features virtual-location-based selective communication: a user can walk freely in the sound room using a map- and cursor-key-based user-interface and can select whom to talk to or which sound sources to listen to. A third feature is SIP-presence-event-notification (SIMPLE)-based sound room management: when users move, their locations and directions are distributed using SIP SUBSCRIBE/NOTIFY messages. The combination of these features creates a natural voice-communication space in which two or more parallel conversation contexts can coexist. Limited, subjective testing by around 200 people showed that this medium can be used for cocktail-party-like conversation; i.e., users could distinguish parallel conversations by paying attention to or by moving toward one of them.

Introduction to this research theme: voiscape

Abstract: A new voice communication medium, which the author calls "voiscape", will probably appear in near future. Voiscape shall have much improved user interface than the conventional voice communication systems, i.e., telephone and conference systems, and be based on the IP-based conferencing and spatial audio technologies. The author has developed a prototype toward voiscape, which has made a step toward solving two problems of the conventional systems i.e., complicated and restricted conference control and lack of crossed-over multi-context support, by introducing two features. The first function is the virtual-location based communication; i.e., the users can talk with other users and move, in a way similar to face-to-face conversation, in a virtual auditory space created by spatial audio technology without explicit session and floor control. The second function is personalized policy-based communication control; i.e., the users can specify communication policies that protects their privacy and reduce required resources. This function is enabled by a distributed policy-arbitration mechanism. Experiments showed that the basic mechanisms and the policy-based control with a simple policy worked well.

Introduction to this research theme: voiscape

Abstract: The author researches toward establishing voice communication media called voiscape which shall replace telephone. A virtual "sound room" that is created by spatial audio technology is used in voiscape. We developed a prototype on PCs, in which 3-D graphic is used for supplementing spatial autio. In this prototype, JMF (Java Media Framework) was used for voice capturing and communication, and Java 3D was used for spatial audio and 3-D graphics. Before the development, the author had believed that the basic functions required for the prototype would be realized by connecting these APIs. However, in fact, they cannot be connected directly, so we used OpenAL through the interface of Java 3D. We also encountered problems of sound quality degradation and delay, but they have been almost solved by refining the program by trial and error.

Introduction to this research theme: voiscape

Abstract: The concept of a new communication medium called voiscape is proposed. A virtual "sound room" that is based on the spatial audio technology is shared among the users in voiscape, and a person can move freely in the room, can meet and depart from other people, and can talk with two or more persons by using voiscape. By enabling transmission of presence and peripheral information, voiscape will cover from a telephone-style one-to-one conversation to a variety of communication types that are impossible in conventional media, and will enable sharing the feeling of connection and releaf and sharing tacit knowledge. This paper describes usage scenes and a procedure of voiscape and also describes a PC-based prototype. In this prototype, the user can confirm the situation in front by 3D graphics, and can move around the room by using a mouse.

Introduction to this research theme: voiscape

Abstract: As part of research toward establishing voice communication media that shall replace telephone, we developed an architecture and a prototype of a continuously-connected multi-user communication medium called voiscape. A virtual "sound room" that is created by spatial audio technology is used in voiscape. When the user moves within the sound room by using a mouse, the presence information including the position in the room is distributed to other users of the room. If the user becomes closer to or more distant from another user, the communication session begins or ends automatically by using SIP according to predefined policy stored in the terminals. This policy-based session control enables privacy protection and reduction of communication. When a local site requires a session start, the remote site often requires a session start concurrently, so a method of establishing a connection without connecting doubly nor becoming busy was deviced.

Introduction to this research theme: voiscape

Abstract: We developed two rule-based building-block architectures, i.e., pipe-connection and label-connection architectures, for describing complex and structured policies, especially network QoS policies. The latter is focused on in this study. The relationships or connections between building blocks are specified by the da-taflow and control flow between them. The dataflow is specified by tags, including virtual flow labels (VFLs), which are data attached to "outside packets". The control flow can be classified and specified by four control structures: concatenation, parallel application, selection, and repetition. We have designed fine-grained and coarse-grained building blocks and methods for specifying dataflow and control flow in differentiated services (Diffserv), and implemented the coarse-grained ones in a policy server. Two cases of building-block use are described, and we concluded that there are five advantages of building-block-based policies, i.e., expressibility, uniform semantics, simplicity, flexibility, and management-task-oriented design. We also developed techniques for transforming building-block policies into executable ones, which are called policy division and fusion.

Introduction to this research theme: Policy-based Networking

要約: This paper proposes a method, called the policy-extension-by-policy method, for quickly and dynamically adding policy classes with new functionality to policy servers and agents. In this method, users can add a new policy class to the policy server by using policy-definition (PD) policies, and they can define a method to translate a policy of the new class and to send to network nodes of different vendors through various types of device interfaces, such as CLI, MIBs, PIBs, APIs or hardware tables, by using policy-embedding (PE) policies. A PE policy also enables translating a policy of an existing class and sending the result to a new type of network node. PE policies contain command templates and methods for filling the templates. A program interpreter is embedded in policy agents to make flexible policy-to-configuration translation possible. A prototype system and example policies, i.e., access control, Diffserv, and VPN policies, were developed.

Introduction to this research theme: Policy-based Networking