Electrical computers and digital processing systems: multicomput – Computer network managing – Network resource allocating
Reexamination Certificate
1998-12-10
2002-11-26
Caldwell, Andrew (Department: 2154)
Electrical computers and digital processing systems: multicomput
Computer network managing
Network resource allocating
C709S233000, C709S249000
Reexamination Certificate
active
06487595
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a mobile Internet protocol for enabling a mobile terminal to access the Internet.
BACKGROUND OF THE INVENTION
The term “Internet” is commonly used to describe an information resource which can be accessed using a host, typically a PC, connected via a modem to a telecommunications network. This resource is stored at many different sites remote from the accessing computer, although each of the remote sites is also linked to the telecommunications network. The Internet is made workable by the specification of a standard communications system which makes use of a number of protocols, Transfer Control Protocol (TCP), User Datagram Protocol (UDP), and Internet Protocol (IP), to control the flow of data around the numerous different components of the Internet. Whilst TCP and UDP are concerned with the prevention and correction of errors in transmitted Internet data, IP is concerned with the structuring and routing of data. Current versions of IP are IPv4 and IPv6.
The Internet is physically constructed from a hierarchy of telecommunication networks, for example local area networks (LANs), regional telephone networks, and international telephone networks. These networks are connected internally and externally by so-called “routers” which receive data from a source host, or a previous router in the transmission chain, and route it to the destination host or the next router in the transmission chain.
FIG. 1
illustrates the case of a source host (SH) and a destination host (DH) coupled to the Internet via respective local area networks (LN) and routers (R).
A host connected to the Internet via a LAN either has an Internet address permanently allocated to it or has an address dynamically allocated by a network server (e.g. using Dynamic Host Configuration Protocol (DHCP)). In the case of a host connected to a telephone network via a modem, the host must request an Internet address from an Internet service provider to which the host subscribes. This is done according to a Point to Point Protocol (PPP) which runs over the IP. In either case, Internet data is routed to the host (possibly via several networks and routers) from some remote source, using the allocated Internet address.
IP defines the transmission of Internet data by way of data packets (“datagrams”). This packet data transfer is one of the main reasons for the success of the Internet as it results in “bursty” transmission which does not require the continuous reservation of a telephone connection and allows many hosts to share the same telephone connections. When a router receives a datagram including a destination address, the router will route the datagram if capacity is available, both in the buffer memory of the router and on the telephone lines. If the router cannot obtain capacity for the datagram then the datagram is rejected and the sending host, or preceding router, must try again at a later time. In general, Internet access is not time critical and the “Best Effort” provided by IP is satisfactory.
Packet data transfer provides efficiencies in data transmission in general, and not only in the retrieval of information from the Internet. For example, packet data transfer may be applied to applications such as voice telephony, video conferencing, and standard data transfer. However, certain of these applications are time critical. Considering real time voice telephony, the Best Effort service provided by IP may result in considerable delays in the transmission of voice data making a received voice signal difficult or impossible to understand. The same applies for the transmission of real time video data. There may also be occasions on which Internet users do not wish to suffer the delays often experienced with conventional Internet data retrieval.
The Internet Engineering Task Force (IETF) is a body which is concerned with the evolution of Internet architecture and the smooth operation of the Internet. The IETF is currently developing a new protocol which will allow a host to request one of a number of reception quality levels (Quality of Service QoS). This protocol is known as Resource ReSerVation Protocol (RSVP. A host uses RSVP to request a specific Quality of Service (QoS) from the network, on behalf of an application data stream which it wishes to receive from some remote host. RSVP carries the request through the network, visiting each router that the network uses to carry the stream. At each router, RSVP attempts to make a resource reservation for the stream. RSVP also attempts to make a resource reservation for the stream at the receiving host and at the sending host.
To make a resource reservation at a node (either a router or a host), the RSVP communicates with two local decision modules, admission control and policy control. Admission control determines whether the node has sufficient available resources to supply the requested QoS. Policy control determines whether the user has administrative permission to make the reservation. If either check fails, the RSVP returns an error notification to the application process that originated the request. If both checks succeed, the RSVP sets parameters in a packet classifier and packet scheduler, at the sending host, to obtain the desired QoS. The packet classifier determines the QoS class for each packet and the scheduler orders packet transmission to achieve the promised QoS for each stream.
RSVP runs over IP, both IPv4 and IPv6. In particular, RSVP is designed to utilise the robustness of current Internet routing algorithms. RSVP does not perform its own routing but instead uses underlying routing protocols to determine where it should carry reservation requests. As routing changes paths to adapt to topology changes, RSVP adapts its reservation to the new paths wherever reservations are in place.
In the current proposed version of RSVP, two QoS levels can be negotiated; Guaranteed Service and Controlled Load Service (in addition to the basic Best Effort service). Guaranteed Service provides both a fixed transmission delay and a fixed bandwidth and is suited to Internet transmissions such as real time voice telephony. Controlled Load Service provides a service level to a data stream which closely approximating the service level that that same data stream would receive from an unloaded network, even when the network is overloaded.
Controlled Load Service is suited to applications where some transmission delay can be tolerated but where it is desired to minimise this delay. In the event that one of these superior QoS levels is not negotiated by RSVP, then Internet data will be received using the conventional Best Effort service. It is possible that in the future RSVP will be extended to provide for the reservation of more than two different additional QoS levels.
With the increased use of mobile cellular telephones, there is a growing demand for so-called mobile Internet access, where access is made from a portable computer connected to a cellular telephone or from an integrated computer/cellular phone device. Currently, subscribers of certain digital cellular telephone networks are able to obtain mobile Internet access by opening a “voice channel” to the cellular network. This channel is reserved for the duration of the Internet “call” and is referred to as a Circuit Switched Data (CSD) channel. A CSD channel is always fully “owned” by a user and thus cannot be violated by other users It will be appreciated that a CSD channel is not efficient for the bursty transmission of Internet data.
Under current proposals, it seems likely that future digital cellular telephone systems will include provision for packet switched transmission channels as well as for circuit switched channels. The general view is that the former will be used for data transmissions, e.g. fax, e-mail, Internet access, whilst the latter will be used for voice calls and possibly combined video/voice calls. In Europe, the current digital cellular telephone standard is known as GSM (Global System for Mobile communications). In the proposed GSM phase
Mikkonen Jouni
Turunen Matti
Caldwell Andrew
Nokia Mobile Phones Limited
Perman & Green LLP
LandOfFree
Resource reservation in mobile internet protocol does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Resource reservation in mobile internet protocol, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Resource reservation in mobile internet protocol will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2924210