Abstract: A system is disclosed that enables the estimation of the location of a wireless terminal in a wireless network. The illustrative embodiment works without requiring modifications to be made to the wireless terminal. Furthermore, the hardware of some embodiments of the present invention can be inexpensively deployed indoors. Some embodiments of the present invention are, therefore, ideally suited for use with legacy indoor systems. The system of the illustrative embodiment of the present invention, in some embodiments, uses an offline process and an online process for location estimation. The described system, however, can be used with other techniques for location estimation.

Abstract: Methods that enable the detection and handling of lost messages during load-balancing routing protocols are disclosed. In accordance with the illustrative embodiment, when a candidate intermediate node N receives a routing-protocol message, node N performs: (1) a first procedure that is capable of detecting some lost routing-protocol messages that were previously transmitted by node N, and (2) a second procedure that is capable of detecting some lost routing-protocol messages that were previously transmitted by a neighbor of node N.

Abstract: An apparatus and methods are disclosed that enable a non-multi-hop wireless terminal (i.e., a wireless terminal that has not been programmed to participate in multi-hop ad-hoc wireless networks) to in fact participate in a multi-hop ad-hoc wireless network, without any changes to the non-multi-hop terminal's software or hardware. In the illustrative embodiment, a wireless terminal T that already belongs to a multi-hop ad-hoc wireless network is assigned to a non-multi-hop wireless terminal W, and a signal is transmitted to terminal W that induces terminal W to use terminal T as a relay for transmitting messages. The assignment of multi-hop-capable terminals in the network to non-multi-hop terminals can be based on a variety of factors, such as signal strengths and the geo-locations of terminals.

Abstract: An apparatus and methods are disclosed that enable load-balancing of routes in ad-hoc wireless networks. In accordance with the illustrative embodiment, when a candidate intermediate node receives a routing-protocol message, the node waits before it transmits a message in response to the received message, where the amount of time that the node waits is based on the value of a load metric at the node and is independent of any other nodes in the network. As a result, a node that has a larger load will wait longer to transmit its routing-protocol message, and consequently, it is less likely that this node will be selected for inclusion in the new route. The techniques of the illustrative embodiment are applicable to both proactive and on-demand routing protocols, and are also applicable to other kinds of networks.

Abstract: A technique is disclosed that attempts to improve the evaluation of a network path's signal quality, as well as the selection of a network path for transmission purposes, without some of the costs and disadvantages of doing so in the prior art. In accordance with the illustrative embodiment, a node with access to the packet network, such as a VoIP telephone endpoint, evaluates the quality of service that is associated with each of multiple network paths. The evaluation process is iterative, in which the number of candidate paths is successively reduced from one iteration of the technique to the next. The multiple paths that remain as candidates in any given iteration are evaluated concurrently and at an evaluation bit rate that i) is less than the full transmission rate of the real-time traffic (VoIP) packets to be sent and ii) varies as a function of the number of candidate paths remaining under consideration.

Abstract: A technique that seeks to direct and re-direct streams of packets through a packet network without adversely affecting the quality of service of existing streams is disclosed. In accordance with the illustrative embodiment of the present invention, streams of packets that are directed and re-directed through a packet network are initially put on probation. During the probation period, a quality-of-service measure for the stream is compared with a threshold whose value is initially high and decreases with time. This has the advantageous affect of noticing problems quickly so that they can be remediated quickly.

Abstract: A method and apparatus are disclosed for estimating the location of a wireless terminal across multiple building floors. The illustrative embodiment determines the floor where the wireless terminal is presently located by using a majority logic-based heuristic. A plurality of signal monitors measure signals from the wireless terminal and provide those signal strength measurements to a location estimation server. Alternatively, the wireless terminal measures signals that are transmitted by a plurality of transmitting signal devices and provides those signal strength measurements to a location estimation server. The location estimation server determines the floor of the wireless terminal in accordance with the illustrative embodiment of the present invention.

Abstract: A method and apparatus are disclosed that seek to improve the quality of service that is experienced during the transmission of a stream of packets across one or more paths. In particular, a transmitting node encodes a source stream of data (e.g., audio, video, etc.) into one or more sub-streams, and distributes those sub-streams onto multiple network transmission paths. In accordance with the illustrative embodiment of the present invention, the transmitting node evaluates the quality of service of a first network path that fails to provide a quality-of-service guarantee. When the quality of service of the first network path becomes unsatisfactory, the coding of one or more sub-streams that are being transmitted on a second network path is adjusted. In other words, the coding on a second channel is adjusted in response to the changing conditions on a first channel.

Abstract: A technique is disclosed that evaluates a network path between (i) a first node in a first subnetwork of endpoint nodes, such as IP phones, and (ii) a second node in a second subnetwork. A “ricochet” node in the network path evaluates the path by probing one or both subnetworks, where the ricochet node acts as relay for traffic packets being transmitted between the two subnetworks. A given relay has only to probe a single, representative node within a subnetwork at any given time in order to obtain performance data that is representative of the subnetwork overall. By probing the representative node, the relay is able to acquire an assessment of network conditions that is valid for the path between the relay and any endpoint in the subnetwork. As a result, the disclosed technique reduces the probing overhead when many endpoint nodes on a given subnetwork are simultaneously active and experiencing adverse network conditions.

Abstract: A method and an apparatus are disclosed that provide a privilege-granting technique for enabling a service-providing domain to grant a privilege to a requesting user in a service-requesting domain. A request handler in the service-providing domain, which comprises one or more service-associated resources, receives a user request to use a service and requests a token from a privilege-granting server, in accordance with the illustrative embodiment of the present invention. Upon receiving the token that specifies a granted privilege from the privilege-granting server, the request handler extends the privilege to the requesting user. Alternatively, the request handler can request a plurality of tokens in advance from the privilege-granting server; after receiving the tokens, the request handler extends a privilege to each requesting user as the handler receives requests to use one or more services.

Abstract: The present invention is a system and method to improve the reliability and performance of existing enterprise IP networks which have dual-homed (or multi-homed) network architectures. In one aspect of the invention packets related to a selected category of transmission (e.g., VoIP) are duplicated at an edge router and sent over both (multiple) service providers. After traversing the service provider networks, only the first-to-arrive packets are kept and the later-arriving copies are discarded. In so doing, the result is better protection against node failures, link failures, and packet errors, and also better QoS performance under normal (fault-free) operation.

Abstract: A method and apparatus are disclosed that enable a call-processing server to extend a received call out to a telecommunications terminal endpoint, wherein the terminal, such as a hotel room phone, is local to and accessible only through an intermediate point, such as a hotel switchboard. Also disclosed are a method and apparatus that enable a data-processing system, such as a server, to determine whether or not to grant a telecommunications terminal endpoint one or more privileges, without some of the disadvantages of the prior art. The methods and apparatus that are taught in this disclosure can be used for extending the incoming call to the endpoint independently of or in the absence of determining whether or not to grant privileges to the endpoint.

Abstract: A method and apparatus are disclosed that enable a data-processing system, such as a server, to determine whether or not to grant a telecommunications terminal one or more privileges, without some of the disadvantages of the prior art. Specifically, in accordance with the illustrative embodiments of the present invention, a call-processing server transmits, to a first terminal, a first signal for verifying a second terminal, such as one that has been designated by a user. The user is then required to transmit a second signal to the call-processing server via the second terminal. The call-processing server then examines the received second signal with respect to the first signal and determines whether or not to grant the second terminal a privilege (e.g., handling calls on behalf of the user, etc.), based on the relationship between the first and second signals.

Abstract: Methods and apparatus are provided for estimating a location of a plurality of wireless terminals. Signal strength measurements are obtained for at least one packet transmitted by each of the wireless terminals; and a Bayesian algorithm is applied to the signal strength measurements to estimate the location of each wireless terminal. In an infrastructure-based deployment, signal strength measurements are obtained from one or more signal monitors. In a client-based model, signal strength measurements are obtained from a client associated with a respective wireless terminal.

Abstract: A method that seeks to provide a satisfactory quality of service for a stream of packets through a network. The illustrative embodiment of the present invention seeks to provide a satisfactory quality of service for a stream of packets by periodically or sporadically evaluating one or more alternative paths through the network and by sending the packets through a path with an acceptable quality of service. Normally, neither the source node nor any other node in a packet's path controls its route after it has left the node. In contrast, the illustrative embodiment of the present invention has the capability to affect the packet's path through the network by sending the packet to an intermediate or “ricochet” node in the network, which forwards the packet to the destination node. In effect, the source node can, if it deems appropriate, ricochet the packet off of the intermediate node rather than allowing the packet to take its normal direct path through the network.

Abstract: A method for providing priority access to 802.11 endpoints. The method includes the steps of sending a Clear To Send (CTS) frame from a designated station, without requiring a Request to Send (RTS) frame from a first station. The CTS frame includes a field identifying the first station for commencing transmission, and a field indicating a duration of transmission. A deferring step is also performed for deferring any transmissions of stations other than the first station until after the duration indicated in the CTS frame has passed.

Abstract: Techniques for performing rapid fault detection and recovery in communication networks are disclosed. For example, in one aspect of the invention, a technique for detecting one or more conditions in a communication network comprises the following steps/operations. One or more keep-alive packets are transmitted from a source node in the communication network to a destination node in the communication network over two or more paths between the source node and the destination node, wherein the two or more paths are at least partially disjoint. Upon receipt of the one or more keep-alive packets at the destination node via the two or more paths, at least one quality measure is computed at the destination node for each of the two or more paths, the at least one quality measure being indicative of one or more conditions in the communication network.

Abstract: A method and apparatus are provided for network security based on a security status of a device. A security update status of a device is evaluated; and one or more of a plurality of security policies are selected to apply to the device based on the security update status. The available security philosophies may include, for example, a “protect the good” philosophy, an “encourage the busy” philosophy and a “shut off the non-compliant” philosophy. The security update status can evaluate, for example, a version level of one or more security features installed on the device or can be based on a flag indicating whether the device satisfies predefined criteria for maintaining one or more computer security protection features up-to-date.

Abstract: A method and apparatus are provided for obtaining a signal strength model for an access point at an arbitrary location, q, at a site. Signal strength measurements are obtained for each of n sampling points; the signal strength received at the arbitrary location, q, is computed from each of said sampling points (for example, using reciprocity principles); signal strength estimates corresponding to the signal received at the sampling points from the arbitrary location are computed; and a signal strength model is determined for an access point positioned at the arbitrary location, q.

Abstract: A system is disclosed that enables the estimation of the location of a wireless terminal in a wireless network. The illustrative embodiment works without requiring modifications to be made to the wireless terminal. Furthermore, the hardware of some embodiments of the present invention can be inexpensively deployed indoors. Some embodiments of the present invention are, therefore, ideally suited for use with legacy indoor systems. The system of the illustrative embodiment of the present invention, in some embodiments, uses an offline process and an online process for location estimation. The described system, however, can be used with other techniques for location estimation.