Cisco Technology, Inc.

Wenfeng Huang

Xiaode Xu

Ian L Sayers

Howard Pines

Huizhao Wang

David Sheldon Stephenson

Daryl Arnold Kaiser

Bretton Lee Douglas

Sheausong Yang

Sandeep Shetty

Rajneesh Kumar

Lu Qian

Kushal A Patel

Michael Chang-Ping Chen

Bhavannarayana Sri Nrusimha Nelakanti

Jason Kim

Sandeep Jay Shetty

A method for providing a handoff in a network environment is provided that includes a mobile station operable to conduct a call. The mobile station is further operable to initiate a call leg autonomously such that a generic transfer function is invoked. The mobile station leverages the generic transfer function in order to execute a handoff for the mobile station.

System and method for executing a seamless handoff in a network environment

Methods, apparatuses and systems directed to facilitating WLAN diagnostics and management using traffic stream metrics. In a data collection stage, according to one implementation of the present invention, localized uplink measurements are taken at a wireless client associated with a wireless access point. During periodic intervals (e.g., every 5 seconds), the wireless client, in one implementation, transmits uplink measurement information to the wireless access point. The wireless access point may also take downlink measurements, which may also include one or more of the following metrics: observed latency, queuing delay, packet loss rate, and packet count information. The wireless access point, in one implementation, may aggregate and report the uplink and downlink metric information to a network management system. In a diagnostic stage, according to one implementation, a wireless network management module performs diagnostics of the WLAN based on the uplink and/or downlink metrics received from the wireless access-point.

WLAN diagnostics using traffic stream metrics

An apparatus and method for switching a mobile processing device from communicating over a wireless connection with a first base unit to a second base unit based upon latency. In accordance with this invention, the mobile processing device determines latency information for packets being transmitted over the wireless connection to and from a base unit. The latency information is compared to a threshold value. If the latency information is greater than the threshold value, the mobile processing device adjusts parameters of the wireless connection between the mobile processing device and the network.

Method and apparatus for optimizing cell operation toward better speech quality in wireless packet-switching networks

A method, an apparatus, and code in a carrier medium to operate in a first access point of a wireless network in communication with at least one associated client station. The method includes wirelessly broadcasting a management frame including an indication that the first access point will stop being active, such that each associated client station can wirelessly roam to a second access point prior to the first access point ceasing being active. One embodiment further includes reducing the transmit power of wireless communication used to wirelessly transmit information to the associated client stations, such that each associated client station can eventually wirelessly roam to the second access point.

Maintaining uninterrupted service in a wireless access point and client stations thereof

A method for evaluating number of additional admissible calls for use in call admission control includes tracking a percentage of channel busy time and transmission time of downlink and uplink voice packets, receiving a call admission request, and calculating the number of admissible calls. The number of admissible calls is calculated based on a channel bandwidth requirement determined from the percentage of channel busy time and a voice packet queuing requirement determined from the transmission time of downlink and uplink voice packets. The call admission request is approved if the number of admissible calls is greater than one and rejected if the number of admissible calls is less than one.

Method and system for evaluting number of additional admissible calls for use in call admission control

The present invention detects a micro-roaming client in a WLAN. Once a micro-roaming client is detected, APs coordinate with each other and assign the client to a specific AP. In an embodiment, a user-configurable anchor timer for micro-roaming clients is provided, so that when the timer has expired, the client is free to roam within the overlapping cell until it becomes anchored to an AP again. In various embodiments, environmental variables can affect APs to release an anchored client to roam again. These environmental variables may include low RSSI from the client, a high percentage of frame loss to the client, or a low data rate. The present invention also provides a new protocol that is resilient and self-sustaining with minimal user configuration required.

Controlling micro-roaming in a wireless LAN

A technique for implementing Special Call Services (SCS) to extend wireless system functionality to include private emergency or other types of service-specific special calls in a private network. In a preferred embodiment, the capability is implemented by taking advantage of certain service type elements that may be coded in the Radio Resource Management (RR) functional layer channel request message and/or the Mobility Management (MM) functional layer call request messages in a Global System for Mobile (GSM) communication system. Specifically, an establishment cause field in a RR channel request message and/or a service type field in a MM request message is used to request such services from the network. These establishment causes and service types can be defined, but not limited to, using those codes currently defined as reserved by GSM Version 4.08, Section 9.1.8 and Section 10.5.3.3. Thus, these newly added codes do not require any re-programming of the deployed GSM equipment and impact on their current operation, either. A GSM system that implements the invention preferably contain a Radio Resource (RR) functional entity that watches for a newly added SCS causes and takes them into account when granting physical resources to the requesting unit. Such actions may include, but are not limited to, dropping a normal call-in-process in order to accommodate the SCS call if there are no free physical resources left, prioritizing SCS calls in progress, or other techniques for allocating a physical channel to the SCS channel request. Such techniques may include allocating radio resources which are reserved in advance for the SCS cause.

Private emergency or service-specific call approach in GSM systems

Error bursts are detected and corrected in a communication system using shortened cyclic codes, such as shortened Fire codes. Data is loaded into a first error syndrome register and a second error syndrome register. The data in the registers may be evaluated to determine if the data bits contain a correctable error. Shortened zero bits are shifted into the second error syndrome register. A number of zero bits are shifted into the first error syndrome register to trap an error burst pattern in the data. A determination is made as to the number of zero bits shifted into the second error syndrome register to trap the location of the error burst in the data. Using the number of zero bits shifted into the second error syndrome register and the error burst pattern, the error in the data is located and corrected.

Method and apparatus for using fire decoder to correct burst errors in a real-time communications system

A method for handover execution in a wireless environment is provided that comprises communicating, by a mobile network, a handover command message to a physical layer of a mobile station to initiate a handover execution. The handover command message is received by the physical layer, which responds by tuning to a handed to frequency and by communicating physical layer bursts over the handed to frequency such that initial timing advance and power control setting characteristics are determined by the mobile network. The method also includes communicating a cease signal to stop communicating the bursts to the mobile station, which responds by ending the transmission of the bursts and by establishing a new communications link over the handed to frequency with the mobile network. The mobile station and mobile network may then couple to a voice or data path such that a wireless communication associated with the mobile station and the mobile network is facilitated.

System and method for handover execution in a wireless environment

A technique whereby a subscriber of a multiple access communication network such as a cellular communication system is permitted to make a reservation to guarantee availability of a shared physical communication resource, such as a cellular radio telephone traffic channel, at an appointed date, time and location. The reservation is made in advance by the subscriber requesting the network to mark a requested resource for the subscribers exclusive use during the requested period of time. The reservation may be made any number of ways, such as through the subscriber terminal itself, by making arrangements themselves or on their behalf by others at a conference call center, through Web servers connected through the Internet, or by other means. Whenever a resource of the requested type is available during the requested period, the controlling stations in the network reserve that resource for that subscribers' exclusive use as the appointed time draws near. Thus, when that subscriber attempts to originate or is expected to receive a call at the appointed time, the network is able to grant the on-hold resource to that subscriber. After the reserved period of time elapses, the network releases the reserved resource, and applies normal allocation rules to it.

Guaranteed air connection

A demodulator determines a time of arrival of an access signal. Access signals that do not result in a time of arrival are discarded. Upon obtaining a time of arrival, the access signal is equalized and a training sequence of bits in the equalized access signal is compared to a reference sequence of bits. A burst confidence metric is obtained in the comparison by summing the number of matching bits. The access signal is discarded if the burst confidence metric is less than a threshold number. A decoder performs a parity check on access signals that have a burst confidence metric exceeding the threshold number. The access signal is discarded if the parity check fails. Upon passing the parity check, the access signal is re-encoded and compared to its received version. If a number of errors from the comparison exceeds a bit error threshold, the access signal is discarded.

Method and system for reducing false detections of access signals

A technique for implementing a flattened Layerstack model within a Global System for Mobile (GSM) communication system so that a centralized multiplex function associated with certain functions handles messages. The multiplex function dispatches radio resource (RR), mobility management (MM), or Connection Management (CM) function messages directly to the respective functional layers without first requiring such messages to pass through a stack. In the preferred arrangement, the multiplex function sub-Lhandles only uplink messages, allowing downlink messages to travel through the sub-layer stack without employing any bridging entity. The multiplex function can run independently of any of the other functions in Layeror can be implemented as part of the message passing part of the Layerrunning body so that the Layermessages are routed directly to a respective RR, MM, or CM function. The flattened protocol stack permits time-sensitive messages related to location update, handover, or cell reselection and other time-critical messages to be handled more efficiently.

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San Ramon, CA, United States of America

Wenfeng Huang