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公开(公告)号：CA2299568A1
公开(公告)日：2000-09-11
申请号：CA2299568
申请日：2000-02-24
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LI JUNYI , VANDERVEEN MICHAELA C , LAROIA RAJIV
Abstract: A base station within a cell of an orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system employs sectorization as a way to reduce the intercell interference. The cell is sectorized from a transmission point of view by the directionality of the downlink antenna, and the OFDM tone set employed in each cell is correspondingly sectorized, i.e., each sector in the cell is allocated a set of tones within a sub-band of the available frequency bandwidth for use when transmitting into that sector. The sub-bands assigned to each sector are periodically changed, or "hopped", among the available sub-bands within the totally available bandwidth. Such subband hopping is a so-called "slow" hopping, in that it is not performed on a symbolby-symbol basis but instead occurs only after more than one symbol has been transmitted in a sector on tones within the sub-band. Each sector employs its own pilot signal, which is assigned one or more tones within the sub-band currently employed by that sector. Similarly, for the uplink, the base station may employ a directional receiver antenna. Preferably, the mobile terminal only transmits on a tone that is within a sub-band that is allocated to the sector in which the mobile terminal is located. This, sub-band, however, need not correspond to the same location within the bandwidth as the sub-band used by the downlink to communicate with the mobile terminal.
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公开(公告)号：AU1677001A
公开(公告)日：2001-08-16
申请号：AU1677001
申请日：2001-02-01
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DAVIES STEPHEN WILLIAM , VANDERVEEN MICHAELA C
Abstract: The defined boundaries in a network are pushed down to the base station level. Doing so necessitates authentication each time a wireless terminal switches communication, or "handoffs" from one base station to another. To achieve such authentication in an efficient manner, security information, i.e., the derived information, is transferred from one base station directly to another. By directly it is meant without accessing any other source of the derived information, although the information may be transferred via other intervening nodes of the network that form an interconnection path for the base stations. A simplified network, i.e., a network with reduced hierarchy from a control point of view, e.g., one that only requires home location register and base station network entities along with interconnection therefore, may be employed with a minimal decrease in performance, e.g., a minimal increase in delay, during the handoff process. In one embodiment of the invention, a first base station which initially receives a service request from a wireless terminal requests authentication information from a central security node and receives in response at least, one, but typically two or more, sets of security information. When it is time for a handoff from the first base station to a second base station, the first base station transmits to the second base station at least one of the sets of security information it received from the central security node. The second base station then uses the information it received from the first base station to authenticate the wireless terminal.
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公开(公告)号：CA2330778A1
公开(公告)日：2001-08-09
申请号：CA2330778
申请日：2001-01-12
Applicant: LUCENT TECHNOLOGIES INC
Inventor： VANDERVEEN MICHAELA C , DAVIES STEPHEN WILLIAM
Abstract: The defined boundaries in a network are pushed down to the base station leve l. Doing so necessitates authentication each time a wireless terminal switch es communication, or "handoffs" from one base station to another. To achieve su ch authentication in an efficient manner, security information, i.e., the deriv ed information, is transferred from one base station directly to another. By directly it is meant without accessing any other source of the derived information, although the information may be transferred via other intervening nodes of the network that form an interconnection path for the base stations. A simplified network, i.e., a network with reduced hierarchy from a control point of view, e.g., one that only requires home location register a nd base station network entities along with interconnection therefore, may be employed with a minimal decrease in performance, e.g., a minimal increase in delay, during the hando ff process. In one embodiment of the invention, a first base station which initially receiv es a service request from a wireless terminal requests authentication information from a central security node and receives in response at least, one, but typically two or more, sets of security information. When it is time for a handoff from the first base station to a second basestation, the first base station transmits to the second base station at least one of the sets of security information it received from the central security node. The second base station then uses the information it received from the first base station to authenticate the wireless terminal.
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公开(公告)号：CA2330723A1
公开(公告)日：2001-08-09
申请号：CA2330723
申请日：2001-01-10
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DAVIES STEPHEN WILLIAM , VANDERVEEN MICHAELA C
Abstract: Paging areas aligned with wireless terminals are dynamically created. A firs t base station passes to the wireless terminal a list of all the base stations that it knows and are within a prescribed number of handoffs of the first base station. The wirele ss terminal uses this list to define its own "personal" paging area. Each time the wireless terminal emerges from a sleep state, it listens for the base station having the best signal and compares its identification against the list of base stations in its persona l paging area. If the best signal base station is on the list, any paging messages for the wireless terminal are automatically broadcast by that base station. Otherwise, the wireless terminal must conduct a handoff to that base station to obtain a new personal paging area centered on that base station with that base station as paging agent. Messages originati ng elsewhere in the network are forwarded to the paging agent for delivery to the wireles s terminal. The paging agent then instructs all known base stations within prescribed number of handoffs of it to page the wireless terminal. The wireless terminal, on hearing the page, will form a connection with the base station having the best signal for communicating. The base station having the best signal for communicating notifies the pagin g agent that it has established a connection with the wireless terminal, which leaves paging mode and becomes active.
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公开(公告)号：BR0000988A
公开(公告)日：2000-10-17
申请号：BR0000988
申请日：2000-03-01
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , LI JUNYI , VANDERVEEN MICHAELA C
Abstract: An orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system using offsetting between cells, and in particular, the use of tone offsetting and time offsetting, is disclosed. More specifically, frequencies that define the tone set of one cell is offset from the frequencies that define the tone set of at least one adjacent cell. In other words, if a first base station is using tones F1, F2, ..., FN within a frequency band, then a second base station adjacent to the first base station uses tones F1+ DELTA f, F2+ DELTA f ..., FN+ DELTA f within the same frequency band. Furthermore, the symbol timing of the base-station of one cell may be offset from the symbol timing of the base-station of an adjacent cell. Thus, if a first base station starts successive symbols at times T1, T2, and T3, then a second base station adjacent to the first base station starts its respective corresponding successive symbols at times T1+ DELTA t, T2+ DELTA t, and T3+ DELTA t. For example, in a cellular system with hexagonally shaped cells, the tone sets of two adjacent cells are offset by 1/3 of the spacing between adjacent tones, and the symbol timings of two adjacent cells are offset by 1/3 of a symbol period. Advantageously, the intercell interference is more uniformly distributed among users in a cell.
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Patent Agency Ranking
公开(公告)号：AU1956600A
公开(公告)日：2000-09-14
申请号：AU1956600
申请日：2000-03-01
Applicant: LUCENT TECHNOLOGIES INC
Inventor： LAROIA RAJIV , LI JUNYI , VANDERVEEN MICHAELA C
Abstract: An orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system using offsetting between cells, and in particular, the use of tone offsetting and time offsetting, is disclosed. More specifically, frequencies that define the tone set of one cell is offset from the frequencies that define the tone set of at least one adjacent cell. In other words, if a first base station is using tones F1, F2, ..., FN within a frequency band, then a second base station adjacent to the first base station uses tones F1+ DELTA f, F2+ DELTA f ..., FN+ DELTA f within the same frequency band. Furthermore, the symbol timing of the base-station of one cell may be offset from the symbol timing of the base-station of an adjacent cell. Thus, if a first base station starts successive symbols at times T1, T2, and T3, then a second base station adjacent to the first base station starts its respective corresponding successive symbols at times T1+ DELTA t, T2+ DELTA t, and T3+ DELTA t. For example, in a cellular system with hexagonally shaped cells, the tone sets of two adjacent cells are offset by 1/3 of the spacing between adjacent tones, and the symbol timings of two adjacent cells are offset by 1/3 of a symbol period. Advantageously, the intercell interference is more uniformly distributed among users in a cell.
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公开(公告)号：BRPI0100193B1
公开(公告)日：2015-08-18
申请号：BR0100193
申请日：2001-01-29
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DAVIES STEPHEN WILLIAM , VANDERVEEN MICHAELA C
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公开(公告)号：DE60104222D1
公开(公告)日：2004-08-19
申请号：DE60104222
申请日：2001-01-29
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DAVIES STEPHEN WILLIAM , VANDERVEEN MICHAELA C
Abstract: Paging areas aligned with wireless terminals are dynamically created. A first base station passes to the wireless terminal a list of all the base stations that it knows and are within a prescribed number of handoffs of the first base station. The wireless terminal uses this list to define its own "personal" paging area. Each time the wireless terminal emerges from a sleep state, it listens for the base station having the best signal and compares its identification against the list of base stations in its personal paging area. If the best signal base station is on the list, any paging messages for the wireless terminal are automatically broadcast by that base station. Otherwise, the wireless terminal must conduct a handoff to that base station to obtain a new personal paging area centered on that base station with that base station as paging agent. Messages originating elsewhere in the network are forwarded to the paging agent for delivery to the wireless terminal. The paging agent then instructs all known base stations within prescribed number of handoffs of it to page the wireless terminal. The wireless terminal, on hearing the page, will form a connection with the base station having the best signal for communicating. The base station having the best signal for communicating notifies the paging agent that it has established a connection with the wireless terminal, which leaves paging mode and becomes active.
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公开(公告)号：AU774407B2
公开(公告)日：2004-06-24
申请号：AU1676201
申请日：2001-02-01
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DAVIES STEPHEN WILLIAM , VANDERVEEN MICHAELA C
Abstract: At least portions of the map of the base stations, i.e., which base stations are neighbors, is discovered and updated using a wireless terminal controlled handoff process. The portion of the map that is discovered by a particular base station is typically its neighbors to which -it can possibly hand off a call it is serving. It takes at least one handoff with each such base station neighbor for the particular base station to discover its entire local map, i.e., all the base stations to which the particular base station can perform handoffs. The wireless terminal handoff process is used to supply a base station with information about other base stations with whom the base station can cooperate to perform handoffs. The handoff process may subsequently be performed more expeditiously between the particular base station and such other base stations using the obtained information. As part of the handoff process, the wireless terminal tells the new base station to which it is handing off the call the identity of the previous base station from which control is being handed off. The wireless terminal then completes handoff and begins to be served by the new base station. If the new base station does not have a valid record for the previous base station, it forms a trust relationship with the previous base station and creates a record for it, thus identifying it as a neighbor to which it can perform expedited handoff in response to the control of a wireless terminal.
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公开(公告)号：BR0100211A
公开(公告)日：2001-10-09
申请号：BR0100211
申请日：2001-01-30
Applicant: LUCENT TECHNOLOGIES INC
Inventor： DAVIES STEPHEN WILLIAM , VANDERVEEN MICHAELA C
Abstract: At least portions of the map of the base stations, i.e., which base stations are neighbors, is discovered and updated using a wireless terminal controlled handoff process. The portion of the map that is discovered by a particular base station is typically its neighbors to which -it can possibly hand off a call it is serving. It takes at least one handoff with each such base station neighbor for the particular base station to discover its entire local map, i.e., all the base stations to which the particular base station can perform handoffs. The wireless terminal handoff process is used to supply a base station with information about other base stations with whom the base station can cooperate to perform handoffs. The handoff process may subsequently be performed more expeditiously between the particular base station and such other base stations using the obtained information. As part of the handoff process, the wireless terminal tells the new base station to which it is handing off the call the identity of the previous base station from which control is being handed off. The wireless terminal then completes handoff and begins to be served by the new base station. If the new base station does not have a valid record for the previous base station, it forms a trust relationship with the previous base station and creates a record for it, thus identifying it as a neighbor to which it can perform expedited handoff in response to the control of a wireless terminal.
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