Telecommunications – Radiotelephone system – Zoned or cellular telephone system
Reexamination Certificate
2000-11-08
2003-07-15
Nguyen, Duc (Department: 2682)
Telecommunications
Radiotelephone system
Zoned or cellular telephone system
C455S560000, C455S552100, C370S467000
Reexamination Certificate
active
06594486
ABSTRACT:
BACKGROUND OF THE INVENTION.
1. Field of the Invention.
The invention relates to radio systems and particularly to non-transparent data transmission in a mobile communication system where a mobile services switching centre and a radio access network belong to different system generations.
2. Description of Related Art
Mobile communication systems generally refer to different telecommunication systems which enable personal wireless data transmission while subscribers roam in the system area. A typical mobile communication system is a Public Land Mobile Network (PLMN). First-generation mobile communication systems were analog systems where speech or data was transferred in an analog form similarly as in conventional public switched telephone networks. An example of a first-generation system is the Nordic Mobile Telephone (NMT).
In second-generation mobile systems, such as the Global System for Mobile Communication (GSM), speech and data are transmitted in a digital form. In addition to conventional speech transmission, digital mobile communication systems provide a plurality of other services: short messages, facsimile, data transmission, etc. Services provided by mobile communication systems can generally be divided into teleservices and bearer services. A bearer service is a telecommunication service which provides signal transmission between user-network interfaces. For example modem services are bearer services. In a teleservice the network also provides subscriber terminal services. Important teleservices include speech, facsimile and videotex services. Bearer services are usually divided into groups according to a property, such as asynchronous and synchronous bearer services. Each of these groups comprises a number of bearer services, such as a transparent service (T) and a non-transparent service (NT). In a transparent service the data to be transmitted is unstructured and transmission errors are corrected only by means of channel coding. In a non-transparent service the data to be transmitted is structured into protocol data units (PDU) and transmission errors are corrected by utilizing (in addition to channel coding) automatic retransmission protocols. For example in the GSM system such a link protocol is called a radio link protocol (RLP). This kind of link protocol is also generally referred to as link access control (LAC).
Currently under development are third-generation mobile communication systems, such as the Universal Mobile Communication System (UMTS) and the Future Public Land Mobile Telecommunication System (FPLMTS), which was later renamed as the International Mobile Telecommunication 2000 (IMT-2000). The UMTS is being standardized by the European Telecommunication Standards Institute (ETSI), whereas the International Telecommunication Union (ITU) standardizes the IMT-2000 system. These future systems are basically very similar. For example the UMTS, as all mobile communication systems, provides wireless data transmission services to mobile subscribers. The system supports roaming, which means that UMTS users can be reached and they can make calls anywhere as long as they are situated within the coverage area of the UMTS.
According to the current view, a UMTS consists of two or three parts, which are illustrated in FIG.
1
: a UMTS access network
1
(or a UMTS base station system UMTS-BSS) and a core network
2
,
3
,
4
and
5
. The UMTS access network will be referred to below generally as a radio access network. The UMTS access network
1
is mainly responsible for matters related to the radio path, i.e. it provides the core network with radio access required for wireless operation. The core network
2
,
3
,
4
or
5
is a conventional or future telecommunication network, which has been modified to utilize the UMTS access network efficiently in wireless communication. Telecommunication networks that are applicable as core networks include second-generation mobile communication systems, such as the GSM (Global System for Mobile Communication), ISDN (Integrated Services Digital Network), B-ISDN (Broadband Integrated Services Digital Network), packet data networks PDN, ATM (Asynchronous Transfer Mode), etc.
Therefore a UMTS access network should enable support for different core networks including networks that will possibly be developed in the future. Correspondingly, UMTS access networks should enable the connecting of different radio interfaces to the core network (narrowband, broadband, CDMA, TDMA, etc.). According to the present scenario the functions of a UMTS access network are strictly limited to radio access functions. Therefore the network mainly comprises functions for controlling radio resources (handover, paging) and for controlling bearer services (radio network service control). The more complicated functions, such as registers, register functions, mobility management and location management, are placed in each core network or in service providers which provide UMTS subscribes with different services and are connected to the core network.
According to UMTS terminology, the entire UMTS access network is called a generic radio access network (GRAN). The GRAN is further divided into a radio access network (RAN) and an interworking unit (IWU). In principle, between each core network
2
-
5
and RAN there is a separate IWU, such as IWUs
1
to
4
shown in the figure. The purpose of the IWU is to provide the connection between the core network and the RAN. Therefore the IWU comprises the required adaptations and other possible interworking functions. The interface between the IWU and the CN is specific to the core network. This enables the development of the core networks and the RAN independently of one another. For example, the IWU may be connected to a base station system BSS in a GSM network. Correspondingly, IWU
2
may be connected to a local exchange in an ISDN network, for instance.
FIG. 1
also shows service providers SP
2
, SP
3
, SP
4
and SP
5
, which are connected to core network CN
2
.
In
FIG. 1
a radio access network RAN comprises a transport network TN, a radio network controller RNC and a base station BS. In the network architecture shown therein, the base stations are connected to the TN, which conveys the user data to the IWUs and the control signalling to the RNC. All the intelligence controlling the GRAN is placed in the base stations BS and in the radio network controller RNC. As stated above, this control is typically limited to control functions related to the radio access as well as to the switching of connections through the transport network. The TN may be, for example, an ATM network. However, it should be noted that only one possible implementation of a UMTS access network is described above.
Transition to the use of third-generation mobile communication systems will take place gradually. At the beginning, third-generation radio access networks will be used in connection with network infrastructure of second-generation mobile communication systems. Such a hybrid system is illustrated in
FIG. 2. A
second-generation mobile services switching centre MSC is connected both to a second-generation radio access network, such as a GSM base station system BSS consisting of a base station controller BSC and base stations BTS, and to a third-generation radio access network consisting of, for example, a radio network controller RNC, an interworking unit IWU and base stations BS. According to a scenario of the GSM MSC, between the MSC and the third-generation radio access network there is preferably a standard A interface. The IWU performs a physical layer conversion, such as a conversion from the ATM to the Primary Rate (E1/T1) and vice versa, and a protocol level conversion, for example a conversion from third-generation rate adaptation and link access protocol (called hereinafter a link access control protocol LAC) to GSM rate adaptation and an L2R/RLP protocol and vice versa in non-transparent transmission, and a signalling conversion, for example from third-generation signalling to GSM A-interface signalling and vice ve
Nguyen Duc
Nokia Corporation
Squire Sanders & Dempsey L.L.P.
LandOfFree
Transparent and non-transparent data transmission in mobile... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Transparent and non-transparent data transmission in mobile..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transparent and non-transparent data transmission in mobile... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3051778