Multiplex communications – Pathfinding or routing – Switching a message which includes an address header
Reexamination Certificate
1999-01-29
2003-11-04
Nguyen, Chau (Department: 2663)
Multiplex communications
Pathfinding or routing
Switching a message which includes an address header
C370S468000, C370S230000
Reexamination Certificate
active
06643290
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, generally, to a method for controlling accesses to resources of a communication network and, more particularly, to a method of expanding time-division multiplex oriented communication networks, particularly time-division multiplex oriented subscriber access networks, for the utilization of current traffic types or services.
2. Description of the Prior Art
In current communication networks designed according to the asynchronous transfer mode (ATM), particularly in subscriber line networks or subscriber access networks such as those designed as passive optical networks (PON) or as fiber coax networks (also referred to as access networks), the available data transmission rate, or the available resources of the communication network, are divided into network termination units. Such units are connected to either the communication network or the communication terminal equipment connected to the network termination units.
The access of the network termination units, or of the communication terminal equipment to the transmission medium used in common (for example, light waveguide or radio channel), is controlled by an algorithm. Such algorithm is typically realized with hardware given the high transmission rates and given a plurality of connected terminal equipment—a network termination unit requesting a communication network resource being therewith granted the access authorization, or access to the transmission medium used in common. For example, the publication “NOVEL ALGORITHM FOR TIME DIVISION MULTIPLE ACCESS IN BROADBAND ISDN PASSIVE NETWORKS,” International Journal of Digital and Analog Communication Systems, Vol. 6, pages 55-62 (1993), M. Glade and H. Keller describes a method for controlling accesses of network termination units to, predetermied resources of a subscriber line network configured as a passive optical communication network.
According to the disclosed method, a timer or counter for each network termination unit, that is started in the framework connection setups derived from the network termination units, is arranged in a network control unit that is centrally arranged in the subscriber line network and connected to each network termination unit. A timer runs down, or the counter reaches a predetermined value, as soon as a new data packet or a specifically reserved memory area is filled with payload data in an affected network termination unit. Such is intermediately stored for data transmission in a buffer memory likewise arranged in the network termination unit. The dimensioning of the counters arranged in the network control unit, or the dimensioning of the time until the expiration of a timer, occurs dependent on the data transmission rates respectively defined, or reserved, during the connection setups. A signalling signal indicating the expiration of a timer represents a network termination unit-associated request for a transmission authorization, or an access to the transmission medium used in common that is sequentially stored in a memory (for example, FTO memory), realized in the network control unit and used in common by all network termination units connected to the network control unit. The stored access requests are read out therefrom and communicated to the connected network termination units, or communication terminal equipment as transmission authorization. As a result, the access to the transmission medium used in common is granted. In the described method, for example, two timers can expire at the same time; i.e., two isochronic access demands would have to be stored and controlled. Since, however, two accesses at the same time are not possible, one of the two access requests is delayed until the current access of the other access request has been terminated. This delay is referred to as a “cell delay variation.” Given expiration of a plurality of timers at the same time, the value of the “cell delay variation” is correspondingly incremented.
It has likewise already been proposed that the access authorizations to the transmission medium used in common requested by the network termination units be directly acquired and stored by a central control Unit Thus, the requested accesss to the transmission medium used in common would be uniformly distributed.
A plurality of traffic types, or service offerings defined by the ATM Porum, are also known from the communication technology according to the asynchronous transfer mode (ATM). According to such technology, high bit rate data transmissions with various demands of, for example, bandwidth and delays are supported or offered by the traffic type; see “ATM & ATM-Management: die Basis für das B-ISDN der Zukunft; LAN-Kopplung über ATM WAN”, Rüidiger Selling, Berlin, Offenbbach: VDE-Verlag, 1997, pages 282-284. For example, voice, images and data can be transmitted over the same terminals via a type of cell multiplex method. The quality of service (QoS) of the individual traffic types and some traffic parameters are negotiated before the connection setup in the framework of the CAC (connection admission control) and are defined in what is referred to as a traffic agreement. The following traffic types, or service offerings, are defined by the ATM Forum:
constant bit rate (CBR),
variable bit rate (VBR),
unspecified bit rate (UBR),
available bit rate (AR).
The traffic types CBR and VBR are particularly suited for applications with high QoS demands such as, for example, multimedia service or video conference circuits with qualitatively high-grade image transmission. In CBR and VBR services, the bandwidth represents an important traffic parameter that is characterize by the specification of a peak cell rate and that must be offered during the entire duration of the connection.
In the traffic type VBR, the further traffic parameters of “maximum throughput rate” and “maximum cell transmission rate” (in cells per second) are also taken into consideration in the connection set up, in addition to the peak cell rate. The maximum throughput rate limits the transmission duration of an ATM cell to the peak cell rate.
The traffic type UBR is a service wherein, by contrast to CBR and VBR, no fixed bandwidth is reserved and a cell loss rate also is not defined. The network, thus, need not offer any resources for a UBR connection that is to be set up, or that is requested.
The traffic type ABR represents a mixture of reserved bandwidth such as in CBR and VBR, and non-reserved bandwidth as in UBR.
SUMMARY OF THE INVENTION
The present invention is therefore directed toward expanding time-division multiplex oriented communication networks, particularly time-division multiplex oriented subscriber access networks for the utilization of current traffic types or services; for example, for utilization of multimedia applications.
In the inventive method for controlling access to resources of a communication network, at least two criteria are selected from the transmission-oriented and switching-oriented properties of the resources of the communication network. Time-division multiplex oriented sub-resources with at least one criterion are allocated to network termination units arranged in the communication network. An important aspect of the inventive method is that a waiting list is provided for each selected criterion, and access requests of the network termination units to the sub-resources are allocated dependent on the selected criteria of the corresponding waiting list with the corresponding waiting list-individual criterion. By cyclically processing the waiting lists, the access to the corresponding sub-resources is granted according to the allocated access requests.
A critical advantage of the inventive method lies in that current, particularly broadband-oriented data services, such as time-critical multimedia services, can be realized in existing communication networks or communication networks to be installed and, in particular, in the subscriber access networks, also referred to as “access networks,” arranged therein. Waiting lists can be
Bell Boyd & Lloyd LLC
Lee Andy
Nguyen Chau
Siemens Aktiengesellschaft
LandOfFree
Method for controlling accesses to resources of a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for controlling accesses to resources of a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for controlling accesses to resources of a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3176855