The invention relates to a method for automatic roaming between heterogeneous WLANs and/or GSM/GPRS/UMTS networks, in which method, for authentication, a mobile IP node (20) requests access to the WLAN at an access point (21, 22), in which method, upon request from the access server (23), the mobile IP node (20) transmits an IMSI stored on a SIM card (201) of the mobile IP node (20) to the access server (23), and in which method, based on the IMSI, using information stored in an SIM user databas...

A method of providing location service for Wireless Local Area Network (WLAN) subscribers. With a location subsystem preset in the WLAN and the WLAN subscribers accessing to a 3G network, the method comprises at least the steps of the WLAN location subsystem detecting whether it has received a location request from an LCS client in the 3G network, if yes, locating the target UE based on the received location request and returning the location result to the Gateway Mobile Location Center (GMLC), ...

A header detection technique for WLAN (Wireless Local Area Network) receivers is provided. The WLAN receiver comprises a signal processing unit that has analog circuitry and digital circuitry. There is further provided a header detection circuit for detecting a header in a received signal. The header detection circuit is comprised in the analog circuitry. In an embodiment, digital circuitry may be woken up based on a header detect signal that is generated by the header detection circuit. The emb...

A method of conserving power in a WLAN receiver is provided wherein processing tasks that need only to be operated for a brief period of time during the reception of a received packet are enabled only during the brief period of time. The enabling includes providing multiple power control signals that are controlled by a state machine for enabling and disabling the processing tasks.

A method and system for conserving power in a WLAN receiver is provided by a channel estimator for detecting transmitted errors in a transmitted packet and providing equalization for the detected channel errors; a separate pilot processor for detecting off set errors from the channel estimation and providing off set correction to said equalization for the whole data portion of the packet after the preamble and a control response to the start of each packet for enabling said channel estimator dur...

An antenna system with two antennas provides the possibility to operate at least two different radio communication systems with one radio communication system operating on one single antenna of the antenna system and another radio communication system operating on both antennas of the antenna system wherein the antenna system serves as a diversity antenna system. This kind of antenna system is designed to be employed particularly in small devices with restricted measurements. Especially, an impl...

A device for processing an intermediate analogue signal received from a previous system with a baseband processor. The processor includes an ordinary feedback loop for adjusting the strength of the intermediate analogue signal received from the previous system. The processor further includes a first DC offset reduction loop and a second DC offset reduction loop. A programmable filter bank and the corresponding control elements are provided so that the second DC offset reduction loop can reduce t...

The admissibility of periodic traffic to a wireless medium can be estimated using a measurement report format that includes a field indicating the number of bins for a predetermined channel of the wireless medium that were busy during a measurement period, and a field indicating the number of bins for the predetermined channel of the wireless medium that were idle during the measurement period. Additionally, the measurement report format includes a field indicating the granularity in multiples o...

A seamless handoff system and method reduces delay and packet loss during handoff of user equipment (UE) from a Wireless Local Area Network (WLAN) network to a Universal Mobile Telecommunication System (UMTS) network. The handoff system and method performs pre-registration and pre-authentication processes before the occurrence of a handoff, buffers packets being delivered to a UE during a handoff period, and forwards the buffered packets to the UE after completion of the handoff, thereby reducin...

A WLAN device operating in an 802.11g mode can receive signals of different modulations. A technique is provided that quickly and accurately identifies signals of different modulation types when received by the WLAN device. This technique includes beginning demodulation of the received signal using components associated with potential types of modulation. One or more identification values can be provided to a voting block for potential types of modulation based on the received signal. The voting...