Abstract: The present invention provides systems and methods for providing distributed, adaptive IP filtering techniques used in detecting and blocking IP packets involved in DDOS attacks through the use of Bloom Filters and leaky-bucket concepts to identify “attack” flows. In an exemplary embodiment of the present invention, a device tracks certain criteria of all IP packets traveling from IP sources outside a security perimeter to network devices within the security perimeter. The present invention examines the criteria and places them in different classifications in a uniformly random manner, estimates the amount of criteria normally received and then determines when a group of stored classifications is too excessive to be considered normal for a given period of time. After the device determines the criteria that excessive IP packets have in common, the device then determines rules to identify the packets that meet such criteria and filters or blocks so identified packets.

Abstract: Transmission methods for multicast messages and for signaling message responses thereto in communication systems supporting a multicast mode provide that a number of retransmissions of a multicast message may be changed based on a number of receivers of the message. Signaling messages to the multicast message may be transmitted in response to a fixed number of multicast message transmissions, and receivers that have not received the multicast message after the fixed number of transmissions may request further retransmissions up to an additional given number of times. Further, signaling messages may be transmitted at different times or staggered based on a radio condition of the receivers. For example, a first multicast message may be transmitted, and responses from groups of receivers may be listened to for a given period, after which one of a next multicast message and a portion of the first multicast message may be transmitted to the groups.

Abstract: In the dynamic access priority method, priority classes with different backoff delays are used to prioritize random access over shared channels and to reduce collision in the presence of a surge of random access requests. Service class information for a plurality of service classes is stored at user equipment. The service class information for a service class includes at least one of a maximum and a minimum back off value; the maximum back off value being indicative of a maximum back off interval and the minimum back off value being indicative of a minimum back off interval. At least one of a maximum and a minimum back off value is determined based on a selected service class of the user equipment, and a back off interval is determined based on the determined back off value. The back off interval indicates a period of time the user equipment waits before the user equipment attempts a transmission.

Abstract: A UMTS (Universal Mobile Telecommunications System) core network supports the negotiation of variable quality of service (QoS). A QoS information element (IE) is defined that supports downgradeable QoS requirements by allowing multiple traffic classes to be specified in a priority order. Similarly, a QoS information element (IE) is defined that supports upgradeable QoS requirements.

Abstract: In a network including a centralized controller and a plurality of routers forming a security perimeter, a method for selectively discarding packets during a distributed denial-of-service (DDoS) attack over the network. The method includes aggregating victim destination prefix lists and attack statistics associated with incoming packets received from the plurality of routers to confirm a DDoS attack victim, and aggregating packet attribute distribution frequencies for incoming victim related packets received from the plurality of security perimeter routers. Common scorebooks are generated from the aggregated packet attribute distribution frequencies and nominal traffic profiles, and local cumulative distribution function (CDF) of the local scores derived from the plurality of security perimeter routers are aggregated.

Abstract: An advance over the prior art is achieved through an efficient method for an admission control algorithm and a scheduling mechanism that complement each other in providing the following three classes of service. A first class of service is termed Class 1 where users specify a nominal amount of bandwidth desired. A second, lower tier service class is termed Class 2, wherein users specify a nominal and minimum amount of bandwidth desired when entering into a network connection. A third server class is Class 3, where Class 3 users are treated as best effort users. For Class 1 users the methodology of the present invention provides a guaranteed nominal amount of bandwidth. The admission control procedure ensures that Class 1 users are admitted only if resources exist to satisfy the nominal bandwidth requirements of the Class 1 users. Class 2 users are admitted if resources exist to satisfy the minimum bandwidth requirements of the user.

Abstract: Method and apparatus for routing messages in a network includes first filters to provide frequency-based message signals converted from an optically-based signal and mixers adapted to mix the frequency-based message signals with sub-carriers to generate frequency-based sub-carrier modulated message signals. A frequency generator connected to the mixers provides the sub-carriers to the mixers and a combiner connected to the mixers combines the frequency-based sub-carrier modulated message signals. Second filters connected to the combiner receive and group the frequency-based sub-carrier modulated message signals. Optical transmitters connected to second filters optically convert and transmit the frequency-based sub-carrier modulated message signals. The frequency generator generates and applies a particular sub-carrier frequency to one of the mixers according to information contained in the frequency-based message signal.

Abstract: A reconfigurable radio access network architecture may connect a base station with different base station controllers. By enabling direct connections between the base station and a plurality of base station controllers, a serving base station controller may directly connected to base stations in soft handoff with a wireless unit, thereby reducing the differential delays between signals received by the base stations. The reconfigurable access system reduces the need for having additional base station controllers beyond the serving base station controller involved in communications with a wireless unit.

Abstract: Method for multicasting messages to users of a wireless communication system includes the steps of establishing a power ratio threshold for transmitting the messages, measuring respective power ratios of the users, comparing the established power ratio threshold to the measured power ratios, determining a first subset of the users and a second subset of the users based upon the measured power ratios and delivering the messages to the first subset of the plurality of users via a first transmission scheme. The first transmission scheme delivers the messages to all of the users of the first subset via a broadcast channel. The method also has a step of delivering the messages to the second subset of the users via a second transmission scheme. The second transmission scheme delivers the messages to each of the users of the second subset via respective dedicated channels.

Abstract: A method, template, protocol, apparatus, system, and computer software for implementing a binary protocol for session initiation in a wireless communications system. The method for creating, modifying or terminating an IP multimedia session among one or more binary session initiation protocol (B-SIP) entities includes providing a flexible template with at least one mandatory field and at least one optional field, wherein the flexible template has fixed and variable length fields, representing a message type with a template id, and maintaining session specific information in a cache.

Abstract: An advance over the prior art is achieved through an efficient method to retransmit erroneous frames by identifying the users who are most likely to experience a frame error and requests retransmissions from them. Since the recovery is done by starting with the most likely, second most likely etc., the invention results in faster recovery of data. Moreover, the invention reduces the battery consumption of subsequent mobile nodes by suppressing the retransmission requests that were already made by nodes preceding it. A key element of the invention is to rank the set of receiver nodes in the order of decreasingly worse channel conditions, i.e., from worst to best. Hence, with K receiver nodes, a transmit node assigns rank 1 to a receiver node to which it has the poorest radio channel condition. Similarly, it assigns rank K to the receiver node to which it has the best radio channel condition.

Abstract: A clustering based load adaptive sleeping protocol for ad hoc networks includes a plurality of nodes forming a cluster, where the nodes in the cluster are partitioned into n groups. This partitioning is performed based on the node ID (e.g. node_id modulo n). The cluster head transmits a beacon at fixed intervals. The beacon interval is divided into N slots, where N is a multiple of n. Node sleep/activation times are synchronized to the beacon interval slots. The node's group number is used to determine the slots within a beacon interval that a node begins it s sleep cycle. Therefore, no additional signaling is required between nodes to indicate sleep patterns. The sleeping time of each node may be increased when extended periods of inactivity are detected according to an adaptive procedure.

Abstract: In a UMTS (universal mobile telecommunications system) Terrestrial Radio Access Network (UTRAN) based wireless system, a wireless network element (e.g., a base station) exchanges information with another wireless network element (e.g., a radio network controller) via data frames (uplink or downlink). Each data frame comprising a header portion and a payload portion, which comprises a QoS class indicator field. Illustratively, the eight bit spare extension field of a UTRAN data frame (uplink or downlink) is used to convey a four bit payload type indicator and a four bit QoS class indicator.

Abstract: In a UMTS network, each packet data service user requires a dedicated channel (DCH) to transmit at high data rates. However, the number of DCHs available is small due to code and power limitations. Thus many users will have to be allocated the same DCH on a time sharing basis. Such sharing will not impact the quality of service for users whose applications are not delay sensitive and whose traffic generation pattern toggles between transmit and idle states. Such applications include web browsing, FTP sessions and E-mail. The present invention discloses four algorithms that can be used to dynamically allocate DCH channels to a contending user based on the user's need according to its traffic generation.

Abstract: A method for access control in a wireless network having a base station and a plurality of remote hosts includes the optional abilities of making dynamic adjustments of the uplink/downlink transmission ratio, making dynamic adjustments of the total number of reservation minislots, and assigning access priorities by message content type within a single user message stream. The method of the invention further provides for remote wireless host paging and for delayed release of active channels by certain high priority users in order to provide low latency of real-time packets by avoiding the need for repeated channel setup signaling messages. In the preferred embodiment, there are N minislots available for contention in the next uplink frame organized into a plurality of access priority classes. The base station allows m access priority classes.

Abstract: An advance over the prior art is achieved through an efficient method for the dynamic selection of frequencies with low occupancy in a manner that results in minimizing the search for such frequencies and the risk of a large of number of nodes choosing the same frequency. A method for dynamically selecting the frequencies according to the invention includes the following parts. A channel loading indicator that determines if the mobile node needs to look for a new channel. A channel search algorithm that quickly determines the new channel to be used. A tracking algorithm that remembers the channels that were most recently determined to be loaded and hence should be avoided in the near future. In one embodiment of the invention a method of selecting frequencies for use by a device in a wireless communications network is presented.

Abstract: A method, apparatus, system, and computer software for compressing and decompressing a message for transmission. The method of compressing a text message for transmission may include parsing text strings and encoding numerical values with a binary representation and analyzing values of the text strings and populating a session specific codebook with partial strings from the values.

Abstract: The present invention sets forth a methodology for providing improved downlink backhaul services from a radio network controller (RNC) to a plurality of base stations via a backhaul network that provides Ethernet services. The Ethernet services are provided by a group of provider edge (PE) switches and regular label switch routers (referred to as P switches). Base stations within the network are assigned into clusters, each of the clusters having a cluster ID. The RNC transmits packets to a given switch or switches out on the network based on a cluster ID included within the transmitted packet. The communications traffic is then multicast from at least one last hop switch in the network to candidate base stations on the basis of the cluster ID and an active set within the cluster. Advantageously, the clusters act as subgroups for more easily directing the transmission of the backhaul multicast traffic.

Abstract: A Layer 2 Tunneling Protocol (L2TP) performs a sender initiated recovery algorithm (SIRA) upon receiving, from an L2TP receiver, a predefined number of packets including the same “next received” (Nr) sequence number. The L2TP sender transmits a payload message that includes the “Reset Sr” (R-bit) indicator, which resets the value for Nr (at the receiver) to either just beyond the first missing packet or to the current send sequence number of the sender.

Abstract: A base station switching system includes a wireless unit that waits before switching from a previous base station to a new base station after the wireless unit has indicated to the wireless communications system the identity of the new base station. Thus, the wireless unit continues to receive data from the previous base station, and the data forwarded to the previous base station will not be lost. For example, whenever a wireless unit decides to switch to a new base station, the wireless unit sends an indication to the wireless communications system of the identity of the selected base station. Before the wireless communications system can forward the data to the new base station, the wireless communications system continues to forward data to the previous base station. To avoid losing such data, the wireless unit continues receiving data from the previous base station.