A method selects suitable frequency bands for data transmission between a network node and a user equipment within a mobile communications network. A network node performs the above mentioned method.
The presented invention is particularly used in the mobile radio communications field.
With respect to UMTS evolution higher transmission rate within the presented licensed frequency bands is required.
Revolutionary air interfaces are proposed which are characterised by higher chip rate crossing multiple UMTS carriers or modulation schemes completely replacing CDMA approach.
An open problem is how to use the existing spectrum to offer higher throughput with reasonable cost.
According to WO 00/51264 a method is known, which is used for implementing downlink diversity in a radio telecommunication system operating according to time divisional multiple access TDMA and including at least one radio transceiver device (and at least on terminal device. The downlink diversity is realized by using frequency and/or time separation.
According to Karol M. J. et al.: “Time-Frequency-Code Slicing: Efficiently Allocating the Communications Spectrum to Multirate Users”, IEEE Transactions on Vehicular Technology, IEEE Inc. New York, US, Vol. 46, No. 4, Jan. 11, 1997, pages 818-826 a time-frequency-code slicing technique is known, which allows multiple users with different data rate requirements access to a communications resource in a manner that is cost effective over a wide range of access rates.
According to WO2004/066646 it is known, that traffic is transmitted over different air interfaces as well as an appropriate synchronisation mechanism. That is an early concept for traffic splitting based on semantic traffic splitting and mainly focuses on end synchronisation algorithms. However, more technical features need to be added in order to obtain the full benefits of the so called Radio Multi-homing concept.
A further approach envisages a generic link layer protocol which also allows traffic splitting or traffic diversity through different air interfaces. But this approach is still in a rudimental level.
Different to them a realistic and more concrete solution for the near term UMTS evolution is proposed. A UMTS network with two frequency layers is assumed. The Extension band (at 2.5 GHz) and the Core band (2 GHz) are studied as use cases. However, for both transmitter and receiver cost reason, neighbouring bundling of carriers are in favour.