Systems, apparatus and methods for estimating a location of a mobile device are presented. Before computing a location estimate, the mobile device groups a plurality of access points into two or more categories (for example, a first list of access points having a first characteristic and a second list of access points having a second characteristic). Round-trip time (RTT) measurements are computed for access points in the first list. A Short Interframe Space (SIFS) value may be determined for each access point in the first list or generally SIFT representing the first list as a whole. The RTT measurements are compensated with the appropriate SIFS value. The mobile device then computes its location or position fix estimate using the compensated RTT values while excluding less accurate RTT values from other access points. As a result, the location estimate eliminates adverse influent from some access points.

A hardware-implemented rate limiter is described. This implementation guarantees that messages containing a value v are not forwarded at a higher rate than a predefined threshold value r. More specifically, given a number of times x in a time interval y, which specifies a rate r defined by x/y, the rate limiter reports a violation by selectively setting an error value when v occurs more than x times during the time interval y. Moreover, the rate limiter may be able to keep track of multiple predefined threshold values for different rates. Furthermore, the rate limiter may keep track of 2.sup.b different values v, where b is the number of digits of the binary representation of v.

One embodiment includes a system. The system includes a receiver configured to extract a timestamp from a header of each packet of a data stream received from a network and to de-packetize the data stream to provide a stream of data blocks. The timestamp can correspond to generation of each data block associated with each respective packet of the data stream according to a global timebase. The system also includes a delay controller configured to measure a delay associated with each packet of the data stream based on the timestamp relative to the global timebase and to control converting the data stream to a corresponding analog output signal for transmission based on the measured delay.

A technique that addresses the problem of a TCP connection's throughput being very vulnerable to early losses implements a pair of controls around ssthresh. A first control is a loss forgiveness mechanism that applies to the first n-loss events by the TCP connection. Generally, this mechanism prevents new TCP connections from ending slow-start and becoming conservative on window growth too early (which would otherwise occur due to the early losses). The second control is a self-decay mechanism that is applied beyond the first n-losses that are handled by the first control. This mechanism decouples of ssthresh drop from cwnd and is thus useful in arresting otherwise steep ssthresh drops. The self-decay mechanism also enables TCP to enter/continue to be slow-start even after fast-recovery from a loss event.

A computer implemented system is provided for improving performance of transmission in real-time or near real-time applications from at least one transmitter unit to at least one receiver unit. The system includes an intelligent data connection manager utility that generates or accesses performance data for two or more data connections associated with the two or more communication networks, and based on the current performance data determining current network transmission characteristics associated the two or more data connections, and bonds the two or more data connections based on: a predetermined system latency requirement; and dynamically allocating different functions associated with data transmission between the two or more data connections based on their respective current network transmission characteristics. The data connection manager utility then manages dynamically the transmission of relatively large data sets across the two or more bonded or aggregated data connections in a way that meets the system latency requirement and improves performance in regards to other network performance criteria (including data transfer rate, errors, and/or packet loss). Related computer implemented methods are also provided.

Methods and systems for finding a packet's routing path in a network includes intercepting control messages sent by a controller to one or more switches in a software defined network (SDN). A state of the SDN at a requested time is emulated and one or more possible routing paths through the emulated SDN is identified by replaying the intercepted control messages to one or more emulated switches in the emulated SDN. The one or more possible routing paths correspond to a requested packet injected into the SDN at the requested time.

A method for transmitting a Voice over Internet Protocol (VoIP) by a wireless LAN Access Point (AP) in a communication system includes when a VoIP frame is input from a terminal, determining whether a buffer for eliminating a jitter generated in a wireless network is used, and storing the VoIP frame in a queue, determining whether the buffer is used, and when the buffer is used, determining a time interval for transmitting the VoIP frame stored in the queue and a service start time, and transmitting the VoIP frame stored in the queue in a wired fashion based on the determined time interval and service start time.

A method for programming route hardware in network devices. The method includes: receiving, by a network device, route updates, selecting from the route updates, a set of selected routes to be used for routing, assigning multiple timestamps to the set of selected routes, programming the set of selected routes into a software-implemented forwarding information base (FIB), segmenting the set of selected routes in the software-implemented FIB into at least a first batch of routes and a second batch of routes, programming the first batch of routes into a hardware-implemented FIB, after the programming, determining a last timestamp, where the last time stamp is the oldest timestamp of the timestamps where all routes associated with the last timestamp have been successfully programmed into the hardware-implemented FIB, and advertising all routes of the first batch that are associated with a timestamp that is no older than the last timestamp.

A method for determining time to live (TTL) of a path of a node including receiving a routing control packet, which includes a first link quality indicating a link quality of a path from the neighbor node to a source node transmitting the routing control packet, from a neighbor node of the node, acquiring a third link quality indicating a link quality of a path from the node to the source node according to a second link quality indicating a link quality of a path from the node to the neighbor node and the first link quality, and determining the TTL of the path from the node to the source node according to the third link quality may be provided. Accordingly, the TTL of the path can be determined more accurately according to a link quality of the path, thereby contributing to ensuring performance and stability of a routing algorithm.

Systems and methods for multiplexing audio/video data and generating transport streams for WiFi network with reduced latency for real time playback at a remote device. A virtual presentation clock reference (PCR) representing a scheduled transmission time of a transport stream packet at a transport stream multiplexer is calculated based on the network transmission rate and generation of the data packets. The virtual PCR is compared with the corresponding system PCR to derive a time difference. Based on the time difference, the transport stream multiplexer is configured to adaptively drop packets or throttle packet generation so as to synchronize the playback of audio/video data on a sink device with the generation of interleaved audio/video packets.