Nortel Networks Corporation

Apple Inc.

Jonathan M Zweig

Darwin A Engwer

James H Woodyatt

Kerry E Lynn

Richard W Mincher

Mahmoud R Amini

Cesar Lozano Villarreal

David C Breece, Iii

Alan B Oppenheimer

Michael W Ritter

Ruenjou Lu

Jeffery L Mullins

Paul McDaid

Joseph M Allem

Systems and methods for enabling a user to obtain rights in a legitimate copy of a digital content unit without downloading the copy from a digital content store are provided. The systems and methods provide an encrypted copy of a digital content unit to a first user and transcript the encrypted copy to generate the legitimate copy to a second user. The encrypted copy is encrypted with a first encrypt key that may be associated with the first user and the legitimate copy is encrypted with a second encrypt key that may be associated with the second user.

Decoupling rights in a digital content unit from download

Methods, systems, and apparatus for selectively communicating data and audio over a limited-size audio plug. A host device determines whether an audio accessory or a data communicating accessory is plugged therein via a signal, or lack thereof, communicated to the host device via the audio plug of the accessory. The host device then either communicates audio or data over the audio plug contacts that are typically used only for audio communication based on whether its connected to an audio accessory or data communicating accessory. An audio plug may also include a split-ring contact where multiple, independent contacts are formed in place of a single tip, ring, or sleeve contact. The split-ring contact may be used for communicating audio and/or data.

Data communications via limited length audio jack

A communication protocol that provides load balancing and/or test pattern information between devices is described. A first embodiment of the protocol provides such information via a data frame that is transmitted a definitive time after a special DTIM beacon is transmitted. This protocol provides full compliance with IEEE 802.11. The second embodiment of the protocol modifies the 802.11 beacon data structure with additional information elements.

Seamless roaming options in an IEEE 802.11 compliant network

In a wireless network system having a wired backbone network, one or more access points (APs), and one or more wireless units (WUs), a technique wherein an AP automatically determines a factor indicative of the error(s) occurring in the transmissions of one or more data packets to associated WUs, and automatically adjust the fragmentation threshold in accordance with the transmission error factor. The AP adjusts the fragmentation threshold in a manner that the data throughput is increased. Since the AP automatically and periodically gauges the wireless medium for RF interference that can cause data transmission errors, the fragmentation threshold can be dynamically adjusted to respond to changes in the wireless medium, such as when a microwave oven is turned on, and/or when a Blue Tooth device is traversing the wireless medium, etc. This is much more effective than having a system administrator periodically gauge the wireless medium for the purpose of selecting the appropriate fragmentation threshold.

System and method for dynamic control of data packet fragmentation threshold in a wireless network

Briefly, in one embodiment, a method for enhancing aggregate data throughput for a number of wireless devices. First, a signal having a first level of effective isotropic radiated power is transmitted by a first wireless electronic device. In the event that a response to the signal is received by the first wireless electronic device, the level of effective isotropic radiated power is reduced to a second level of effective isotropic radiated power. In another embodiment, the aggregate amount of data throughput may be enhanced by monitoring a level of effective isotropic radiated power associated with at least one beacon produced by the first wireless electronic device on a first communication channel. The level of effective isotropic radiated power of the beacon is then reduced if the monitored level is greater than a predetermined power level threshold.

Dynamic power level control on transmitted messages in a wireless LAN

A protocol for acknowledging receipt of a multicast or broadcast frame by a wireless unit is described. One embodiment, an Eavesdrop Unicast frame is created for use in a wireless network operated in accordance with IEEE 802.11. The Eavesdrop Unicast frame allows the targeted wireless unit to transmit acknowledgement (ACK) frame but is configured so that other wireless units can scan and obtain information therefrom. Another embodiment is similar in configuration to the Eavesdrop Unicast frame but is fully compliant with IEEE 802.11. Therein, a multicast or broadcast frame is transmitted but one wireless unit is configured to acknowledge receipt of the multicast or broadcast frame. The acknowledgement is accomplished through transmission of a data frame. Yet another embodiment is the transmission of broadcast or multicast frames into corresponding unicast frames.

Reliable broadcast protocol in a wireless local area network

In a wireless network system comprising a wired backbone network, an access point, and one or more associated wireless unit data coupled to the access point by way of a wireless transmission medium, a method of enabling fragmentation of data packet above a fragmentation threshold in one or more wireless units, comprising transmitting a message to the one or more wireless unit having a first control data that causes the one or more wireless units to implement fragmentation threshold in transmitting data packets to the access point. The message is preferably a multicast data packet intended for the one or more associated wireless units. The message may further include a specified fragmentation to be used, and also another control signal for enabling request to send (RTS) and clear to send (CTS) transmission by the one or more wireless units.

Automatic distribution of RTS and frag thresholds

In a wireless network system having a wired backbone network with two or more sub-networks, each having one or more access points for communicating with wireless units via a wireless transmission medium, a system, apparatus and method for a wireless unit to determine whether a candidate access point is on a different sub-network than its current access point. If the wireless unit determines that the candidate access point is on a different sub-network, then the wireless unit releases its current network protocol address which was valid for the current sub-network, and obtains a new network protocol address valid for the new sub-network. This is accomplished by the candidate access point transmitting a multicast packet that includes the network protocol address of the access point and the subnet mask of the sub-network which the access point is on. By receiving this multicast packet, the wireless unit can determine if the candidate access point is on a different sub-network than its current sub-network. Also disclosed is a technique for a wireless unit to determine whether to roam to a candidate access point based on the signal qualities to its current and candidate access points, and whether the candidate access point is on a different sub-network or a designated restricted sub-network.

System and method for a wireless unit acquiring a new internet protocol address when roaming between two subnets

Apparatus for use with a cable for interconnecting electronic devices is described. The apparatus includes an indicator for identifying a characteristic of the cable, and includes a mechanism operable to cause the indicator to identify the characteristic of the cable. The indicator can be for example an LED and can be used to identify the location of an end of the cable. The mechanism can be a pushbutton located at the other end of the cable. The LED is illuminated when the pushbutton is activated. A signal generator is responsive to the pushbutton and provides a signal to the LED to cause the LED to illuminate. The signal generator can be implemented with a DMTF encoder.

Self-identifying cable for interconnecting electronic devices

In one embodiment, an authentication method features the generation of an initialization vector at a first electronic device and the determination at the first electronic device whether the initialization vector falls within a first group of initialization vectors. The first group includes a plurality of initialization vectors solely used in connection with an authentication sequence. Information is encrypted using in part the initialization vector for return to a second electronic device if the initialization vector falls within the first group.

Wireless LAN WEP initialization vector partitioning scheme

A method and apparatus for assigning a unique network address to a first node within a network which is arbitrarily connected. The first node may include a shared network resource, such as a networked printer device, or a modem, in addition to a stand-alone computer system. The network may include a network which is wireless, wherein various nodes comprise radio transceiver circuitry, including radio frequency modems. A first provisional network address for use in assigning the unique network address is determined by the first node. The first node broadcasts probes containing the provisional network address until a first probe response to one of the probes is received or a first interval of time elapses. If the first probe response to one of the probes is received, then the first node determines a second provisional network address and repeats selection of the address and broadcasting, until no probe response is received in the first interval of time. Using the first provisional network address, the first node broadcasts forward probes in the network until a second probe response to one of the forward probes is received by the first node or a second period of time has transpired. If a second probe response to one of the forward probes is received by the first node, then the first node determines a third provisional network address and repeats the steps of selecting, broadcasting probes and forward probes until no the response is received in the second interval of time. The final provisional network address may be used as the unique network address for the first node.

Dynamic address assignment in an arbitrarily connected network

A method and apparatus for decryption using cache storage wherein imported ciphertext is decrypted to produce unencrypted plaintext data. As a communication sequence containing an initialization vector and a block of ciphertext is imported, the initialization vector is applied to a cache and to a decoder. The initialization vector is then compared with other initialization vectors stored in the cache to determine whether the specific initialization vector has previously been received and stored. If the specific initialization vector is found to be stored in the cache, then the PN sequence associated with that initialization vector is written to the decoder, and the stored PN sequence is used to decode the imported ciphertext. If a determination is made that the initialization vector has not been previously received, then the read cache signal instructs the multiplexer to connect the PN generator to the decoder, and the initialization vector is used to generate a new PN sequence. In order to improve the efficiency of future ciphertext decoding utilizing this specific initialization vector, the PN sequence associated with the initialization vector is then stored in the cache together with its corresponding initialization vector. When the next block of ciphertext is received using the same initialization vector, the PN sequence need not be regenerated by the PN generator, but rather may be read from the cache as a stored sequence.

Method and apparatus for decryption using cache storage

A digital encryption structure allows the varying of the computational overhead by selectively reusing, according to the desired level of security, a pseudorandom encoding sequence at the transmitter end and by storing and reusing pseudorandom decoding sequences, associated with one or more transmitters at the receiver end. A public initialization vector is combined with a secret key to produce a deterministic sequence from a pseudorandom number generator. This pseudorandom sequence in turn, is used to convert plaintext to ciphertext. The sequence may be selectively reused by storing the sequence to a transmitter memory cache and iteratively reading the sequence from memory according to a counter which controls the level of security of the encryption system. The ciphertext is decrypted on the receiver end by invertibly combining the ciphertext with the same pseudorandom sequence used by the transmitter to originally encode the plaintext. The pseudorandom sequence is independently generated by the receiver end using the original key and initialization vector used in the transmitter end. Once generated in the receiver, the pseudorandom sequence is stored in a receiver cache for reuse with each iterative use of the stored transmitter pseudorandom sequence.

Growing community of inventors

Cupertino, CA, United States of America

Jonathan M Zweig