Abstract: A wireless endpoint employs frequency hopping for communicating signals in a wireless communications system. Over a time period T, the wireless endpoint performs pseudo-random selection of a frequency from a hopping set of N frequencies such that over at least a portion of the time period T, the frequency selection is constrained to less than the N frequencies.

Abstract: In a multiple node network, the method includes waking up at least one node from a sleep mode during at least one associated slot of a time-slotted frame, the sleep mode being a low power consumption mode. Also, in at least one node of a multiple node network, the period of time a node sleeps is based on the residual energy of the node, the residual energy of the nodes in the neighborhood, neighborhood node density, and combinations thereof.

Abstract: In the method for selecting a channel rate, link quality between the serving portion of the network and a mobile station is determined from at least one signal strength measurement. A channel rate is then selected based on the determined link quality. Also, a physical channel is assigned to the mobile station on a prioritized basis with respect to the selected channel rate.

Abstract: Systems and methods for intelligently assigning a channel to a device being used by a mobile user in a power controlled, wireless communications system by minimizing the difference between a mobile user's received signal power and the minimum received signal power of a current user on a candidate carrier frequency. Each carrier frequency within a cell is examined to determine whether it has at least one current user assigned to a channel and also has at least one unoccupied channel. For each carrier frequency that meets both of these requirements, a channel quality metric is obtained for each occupied channel. The carrier frequencies are pruned down to a subset of candidate carrier frequencies using the channel quality metrics. Finally, a channel within the set of candidate carrier frequencies is selected by computing a cost function based on the received signal power of the mobile user and the received signal power of each occupied channel.

Abstract: An adaptive pulse position modulated CDMA scheme for use in UWB communications systems is disclosed. A stream of input bits is encoded with spreading code sequence. The spreading code sequence consists of a number of code elements that may have one of two values. Each bit is encoded into a symbol consisting of a predefined number of chips, which are transmitted during a symbol period. Next, at least one code element is associated with each chip in the symbol. Then, an encoded pulse is generated in each chip. Each encoded pulse has a value determined by multiplying the data bit with the code value associated with the particular chip. The encoded pulse is then pulse position modulated by shifting the position of the pulse to a first position or a second position within the chip depending upon the encoded value of the pulse.

Abstract: Methods and systems for generating a variable spacing pulse position modulated (VSPPM) signal for transmission across an ultra-wideband communications channel. The variable pulse position modulated spread spectrum signal is created by encoding every M input data bits from an input data stream into a symbol consisting of Nc chips. Each chip is divided into 2M sub-chips and each sub-chip is further divided into Np time slots. A pulse is transmitted for each chip in the symbol. During each chip period, the pulse is placed in the sub-chip corresponding to the binary M-tuple (or symbol) value. A time hopping code sequence consisting of Nc elements with a one-to-one chip association is then applied to each symbol so that the position of each pulse is shifted to the appropriate time slot that corresponds to the time hopping code value.

Abstract: A wireless endpoint employs frequency hopping for communicating signals in a wireless communications system. Over a time period T, the wireless endpoint performs pseudo-random selection of a frequency from a hopping set of N frequencies such that over at least a portion of the time period T, the frequency selection is constrained to less than the N frequencies.

Abstract: A rasp tool including a handle member, a cutter member, and a releasable locking mechanism for selectively coupling the handle and cutter members. The locking mechanism includes a locking post on the cutter member and a corresponding post-receiving bore in the handle member. A spring-biased locking key is disposed within a guide bore that intersects the post-receiving bore such that the locking key extends partially into the post-receiving bore. As the locking post is axially introduced into the post-receiving bore, the locking post contacts the locking key and causes it to retract until the locking post is fully received within the bore, at which point the spring-biased locking key engages a transverse notch in the locking post, thereby preventing axial removal of the post from the bore. The locking key is disengaged from the locking post by a manually-actuable trigger coupled to the locking key.