Abstract: Aspects of a method and system for compensating for estimated distortion in a transmitter by utilizing a digital predistortion scheme with a quadrature feedback mixer configuration are presented. Aspects of the system may include an RF transmitter that enables generation of an RF output signal in response to one or more generated input signals. One or more feedback signals may be generated by performing frequency downconversion on the RF output signal within a corresponding one or more feedback mixer circuits. The generated one or more feedback signals may be inserted at a corresponding one or more insertion points in an RF receiver. Each insertion point may be between a receiver mixer circuit and corresponding circuits that generate a baseband signal based on the corresponding one of the feedback signals.

Abstract: Aspects of a method and system for compensating for estimated distortion in a transmitter by utilizing a digital predistortion scheme with a quadrature feedback mixer configuration are presented. Aspects of the system may include an RF transmitter that enables generation of an RF output signal in response to one or more generated input signals. One or more feedback signals may be generated by performing frequency downconversion on the RF output signal within a corresponding one or more feedback mixer circuits. The generated one or more feedback signals may be inserted at a corresponding one or more insertion points in an RF receiver. Each insertion point may be between a receiver mixer circuit and corresponding circuits that generate a baseband signal based on the corresponding one of the feedback signals.

Abstract: An end host redundancy elimination system and method to provide redundancy elimination as an end system service. Embodiments of the system and method use optimization techniques that reduce server central processing unit (CPU) load and memory footprint as compared to existing approaches. For server storage, embodiments of the system and method use a suite of highly-optimized data structures for managing metadata and cached payloads. An optimized asymmetric max-match technique exploits the inherent structure in data maintained at the server and client and ensures that client processing load is negligible. A load-adaptive fingerprinting technique is used that is much faster than current fingerprinting techniques while still delivering similar compression. Load-adaptive means that embodiments of the fingerprinting technique can adapt CPU usage depending on server load.

Abstract: A method and apparatus is described to select a representative signature for use in identifying content in a packet stream. The method may comprise receiving the packet stream and obtaining content from a data payload of the packet. Thereafter, a plurality of signatures is identified from the content and a complexity score or a frequency score is determined based on the content. A signature of the plurality of signatures is then selected as the representative signature based on the complexity score or the frequency score.

Abstract: Detecting attacks against computer systems by automatically detecting signatures based on predetermined characteristics of the intrusion. One aspect looks for commonalities among a number of different network messages, and establishes an intrusion signature based on those commonalities. Data reduction techniques, such as a hash function, are used to minimize the amount of resources which are necessary to establish the commonalities. In an embodiment, signatures are created based on the data reduction hash technique. Frequent signatures are found by reducing the signatures using that hash technique. Each of the frequent signatures is analyzed for content, and content which is spreading is flagged as being a possible attack. Additional checks can also be carried out to look for code within the signal, to look for spam, backdoors, or program code.

Abstract: A method and apparatus for detecting malicious attacks is described. The method may comprise obtaining routing information from a packet communicated via a network and maintaining a count of packets associated with a device associated with the routing information. For example, the routing information may a source or destination IP address, a port number, or any other routing information. The device may be classified as a potentially malicious device when the count exceeds a threshold. The count may be incremented when the TCP SYN flag is set and the TCP ACK flag is not set. An embodiment comprises obtaining a source hash of the source IP address and a destination hash of the destination IP address. Thereafter, the source hash and the destination hash may be mapped to multi stage filters. The device associated with the packet may then be selectively categorizing as a suspicious device.

Abstract: Various improvements are provided for prior art policing methods, including token bucket methods and virtual time policing methods. Some preferred methods of the invention involve assigning a non-zero drop probability even when the packet would otherwise have been transmitted according to a prior art policing method. For example, a non-zero drop probability may be assigned even when there are sufficient tokens in a token bucket to allow transmission of the packet. A non-zero drop probability may be assigned, for example, when a token bucket level is at or below a predetermined threshold or according to a rate at which a token bucket is being emptied. Some implementations involve treating a token bucket as a virtual queue wherein the number of free elements in the virtual queue is proportional to the number of remaining tokens in the token bucket.

Abstract: A method and device to process a packet received by a network device is described. The method may comprise analyzing the packet to identify at least one set of a plurality of sets, mapping the at least one set to at least one functional unit, and performing functionality associated with the at least one functional unit. Analyzing the packet to identify at least one of a plurality of sets may comprise determining when the packet includes at least one set identifier, and identifying the at least one set based on the at least one set identifier. A set status identifier may be defined for each set, the set status identifier indicating when set identifiers associated with a corresponding set are detected in the packet. The device may be a router, switch or any other device that processes digital data e.g., packet data including packets headers, payload or the like.

Abstract: A non-enzymatic electrochemical method of simultaneous measurement of hemoglobin (Hb) and percentage of glycated hemoglobin (% HbA1c) in a blood sample is disclosed. The method includes determining the total amount of hemoglobin in a sample by electrochemically measuring the voltammetric current due to iron (II) and iron (III) redox portions in hemoglobin and determining the percentage of glycated hemoglobin (HbA1c) by potentiometry. Also disclosed is a novel screen-printed electrode (SPE) strip modified for potentiometric measurement of HbA1c.

Abstract: Embodiments of the invention relate to a method and apparatus for a zero voltage processor sleep state. A processor may include a dedicated cache memory. A voltage regulator may be coupled to the processor to provide an operating voltage to the processor. During a transition to a zero voltage power management state for the processor, the operational voltage applied to the processor by the voltage regulator may be reduced to approximately zero and the state variables associated with the processor may be saved to the dedicated cache memory.

Abstract: A method and apparatus is described for identifying content in a packet. The method may obtain data sample from the packet where the data sample is in a predetermined window at an initial offset point in the packet. For each offset point, a first stage of processing on the data sample may be performed to identify if the data sample corresponds to potentially relevant reference string. A more focused second stage of processing may then be carried out on the data sample to identify if the data sample corresponds to potentially relevant reference string. Thereafter, an even more focused third stage of processing may be carried out on the data sample to obtain a third stage result. If the data sample passes all three stages of processing, a predefined action is identified which is associated with a reference string corresponding to the data sample.

Abstract: Aspects of a method and system for estimating and compensating for non-linear distortion in a transmitter using calibration are presented. Aspects of the system may include one more circuits that may enable estimation, within a single IC device, of distortion in output signals generated by a transmitter circuit. The circuitry may enable compensation of the estimated distortion by predistorting subsequent input signals. The transmitter circuit may generate subsequent output signals based on the predistorted subsequent input signals.

Abstract: A method and apparatus is described to process packets in a network. The method may comprise receiving the packet and determining a length K of the packet. If the length of the packet is less than a reference length M then no analysis may be performed on the packet. However, if the packet length K is not less than M, the method may determine if the packet length K is at least greater than a reference window size WRef. When the packet length is greater than WRef then a window size W for the processing of the packets is set equal to WRef; and the packet length is less than WRef then a window size W for the processing of the packets is set equal to the packet size K. Thereafter, the packet is processed using the window size W.

Abstract: Network worms or viruses are a growing threat to the security of public and private networks and the individual computers that make up those networks. A content sifting method if provided that automatically generates a precise signature for a worm or virus that can then be used to significantly reduce the propagation of the worm elsewhere in the network or eradicate the worm altogether. The content sifting method is complemented by a value sampling method that increases the throughput of network traffic that can be monitored. Together, the methods track the number of times invariant strings appear in packets and the network address dispersion of those packets including variant strings. When an invariant string reaches a particular threshold of appearances and address dispersion, the string is reported as a signature for suspected worm.

Abstract: A method and device to process a packet received by a network device is described. The method may comprise analyzing the packet to identify at least one set of a plurality of sets, mapping the at least one set to at least one functional unit, and performing functionality associated with the at least one functional unit. Analyzing the packet to identify at least one of a plurality of sets may comprise determining when the packet includes at least one set identifier, and identifying the at least one set based on the at least one set identifier. A set status identifier may be defined for each set, the set status identifier indicating when set identifiers associated with a corresponding set are detected in the packet. The device may be a router, switch or any other device that processes digital data e.g., packet data including packets headers, payload or the like.

Abstract: Aspects of a method and system for estimating and compensating for non-linear distortion in a transmitter using data signal feedback are presented. Aspects of the system may include a method and system by which predistortion values, for compensating for non-linear distortion, may be computed based on feedback signals generated in response to wideband input signals. The wideband input signals may comprise a plurality of frequency components and/or signal amplitudes. The predistortion values may be computed by time-synchronizing a wideband input signal generated at a given time instant, and the feedback signal generated at a subsequent time instant in response. A predistortion function may be computed by computing predistortion values for a plurality of signal amplitude values and/or IC operating temperatures. The computed values may be stored in a lookup table and retrieved to predistort subsequent wideband input signals based on the amplitude of the signals and/or the IC operating temperature.

Abstract: Various improvements are provided for prior art policing methods, including token bucket methods and virtual time policing methods. Some preferred methods of the invention involve assigning a non-zero drop probability even when the packet would otherwise have been transmitted according to a prior art policing method. For example, a non-zero drop probability may be assigned even when there are sufficient tokens in a token bucket to allow transmission of the packet. A non-zero drop probability may be assigned, for example, when a token bucket level is at or below a predetermined threshold or according to a rate at which a token bucket is being emptied. Some implementations involve treating a token bucket as a virtual queue wherein the number of free elements in the virtual queue is proportional to the number of remaining tokens in the token bucket.

Abstract: A method and system to detect an evasion attack are provided. The system may include a repository to store signature fragments that together constitute an attack signature, an interceptor to intercept a data packet associated with a network connection, a string-matching module to determine whether the payload of the data packet includes any of the stored signature fragments thereby identifying a match, a responder to perform a prevention action in response to the match, and a detector to detect that a size of the data packet is less than a size threshold. The system may further include a state machine to commence maintaining a state for the network connection in response to the detector determining that the size of the data packet is less than the size threshold.

Abstract: Devices, networks, and methods are disclosed for providing a plurality of answering message options to a called party for answering an incoming call. When a call is received in a called device, the called device identifies a plurality of answering messages predefined by the called party. The called device then provides answering message options to the called party based on the identified answering messages. The called party selects one of the answering message options. Responsive to the selection by the called party, the called device and/or the communication network transmits an answering message to the calling party. The answering message in essence “answers” the call for the called party. The called party does not actually have to speak into the called device to answer the call.

Abstract: A method and apparatus is described to select a representative signature for use in identifying content in a packet stream. The method may comprise receiving the packet stream and obtaining content from a data payload of the packet. Thereafter, a plurality of signatures is identified from the content and a complexity score or a frequency score is determined based on the content. A signature of the plurality of signatures is then selected as the representative signature based on the complexity score or the frequency score.