초록 ▼

A method and system are disclosed for facilitating the timing (e.g., the known relative timing differences) of base stations (BSs) in asynchronous CDMA mobile communications systems. A plurality of mobile stations (MSs) measure the relative time differences between various pairs of BSs, and these me

A method and system are disclosed for facilitating the timing (e.g., the known relative timing differences) of base stations (BSs) in asynchronous CDMA mobile communications systems. A plurality of mobile stations (MSs) measure the relative time differences between various pairs of BSs, and these measurements are stored by the BSs. A source BS sends to an MS, in a neighbor list message, estimates of the relative time difference between the source BS and each of the BSs on the neighboring cell list. Each BS on the list can maintain a relative time difference estimate table, which can be updated continuously from the reports received from MSs. Subsequently, the BSs can send entries from this table to the MS in the neighbor list message. Using this novel technique, the BSs have known relative timing differences. Consequently, when the MS initiates a cell-search for a candidate BS, the MS already has an estimate of the timing of that BS as compared to its source BS. As such, the resulting cell-search procedure has a lower level of complexity and thus can be accomplished much quicker than with prior procedures. In addition, the relative time difference estimates can be compared with corresponding time differences that are measured by a second mobile station. Based on this comparison, the propagation delays of signals between the second MS and various BSs can be calculated to determine the position of the second MS.

대표청구항 ▼

A method and system are disclosed for facilitating the timing (e.g., the known relative timing differences) of base stations (BSs) in asynchronous CDMA mobile communications systems. A plurality of mobile stations (MSs) measure the relative time differences between various pairs of BSs, and these me

A method and system are disclosed for facilitating the timing (e.g., the known relative timing differences) of base stations (BSs) in asynchronous CDMA mobile communications systems. A plurality of mobile stations (MSs) measure the relative time differences between various pairs of BSs, and these measurements are stored by the BSs. A source BS sends to an MS, in a neighbor list message, estimates of the relative time difference between the source BS and each of the BSs on the neighboring cell list. Each BS on the list can maintain a relative time difference estimate table, which can be updated continuously from the reports received from MSs. Subsequently, the BSs can send entries from this table to the MS in the neighbor list message. Using this novel technique, the BSs have known relative timing differences. Consequently, when the MS initiates a cell-search for a candidate BS, the MS already has an estimate of the timing of that BS as compared to its source BS. As such, the resulting cell-search procedure has a lower level of complexity and thus can be accomplished much quicker than with prior procedures. In addition, the relative time difference estimates can be compared with corresponding time differences that are measured by a second mobile station. Based on this comparison, the propagation delays of signals between the second MS and various BSs can be calculated to determine the position of the second MS. ed, wireless communication path is available and connects to the LAN using a longer range, lower speed wireless communication path if the short-range, high-speed wireless communication path is not available. The low-range, high-speed wireless communication path is a wireless LAN connection such as an IEEE 802.11-compliant wireless LAN and the long-range, low-speed wireless communication mode is a cellular CDMA-type connection. Determining whether the first IEEE 802.11 mode is available can be done by detecting a beacon signal, or by transmitting a probe request message and detecting a probe response message in response to the probe request, indicating the presence or availability of the short-range, high-speed wireless communication path. Alternatively, the availability of short-range, high-speed wireless communication path can be detected by simply detecting activity on it. ice provider's network; and obtaining a Mobile IP shared secret from the voice and data service provider's network, wherein the step of setting up call forwarding from the home wireless network to the voice and data service provider's network further comprises: obtaining a telephone number for call forwarding from the voice and data service provider; and obtaining the IP address of the HA in the home H.323 server from the voice and data service provider, wherein the step of registering with a visited H.323 server in the visited wireless network to establish the second end of the IP tunnel within the FA further comprises: obtaining a dynamic IP address from the home H.323 server by the visited H.323 server using Dynamic Host Configuration Protocol (DHCP); relaying the dynamic IP address from the home H.323 server via the visited wireless network to the user's mobile device; authenticating the connection by the user's mobile device using the Mobile IP shared secret; and establishing the IP tunnel by the user's mobile device. 2. The method as in claim 1, further comprising: collecting billing information from the visited wireless network by the visited wireless service provider; and billing the user by the visited wireless service provider responsive to the billing information collected and the user's identified payment means. 3. The method as in claim 2, wherein the user's payment means comprises credit card information and wherein the step of identifying the user's payment means to the visited wireless network further comprises: establishing a Diffie-Hellman temporary shared secret between the user's mobile device and the visited wireless network; securely transmitting the user's credit card information to the visited wireless service provider via the visited wireless network using the temporary shared secret; and verifying the validity of the user's credit card information by the visited wireless network. 4. The method as in claim 3, wherein the step of securely transmitting the user's credit card information further comprises retrieving previously stored credit card information within the user's mobile device. 5. The method as in claim 3, wherein the step of securely transmitting the user's credit card information further comprises the user entering credit card information into the user's mobile device. 6. The method as in claim 1, wherein the step of establishing the IP tunnel further comprises: updating a phone-number-to-IP-address table in the home H.323 server; updating a mobility binding table in the HA; and updating a IP-address-to-phone-number table in the visited H.323 server. 7. The method as in claim 1, wherein the step of delivering calls to the user's mobile device via the IP tunnel further comprises: conversion of a circuit call for delivery to packets by the home H.323 server; forwarding the packets via the established IP tunnel; reassembling the forwarded packets into a reassembled circuit call by the visited H.323 server; and transmitting the reassembled circuit call over-the-air to the user's mobile device via the visited wireless network. 8. The method as in claim 7, wherein the step of delivering calls to the user's mobile device via the IP tunnel further comprises: receiving a response over-the-air from the user's mobile device by the visited wireless network; conversion of the response to packets by the visited H.323 server; forwarding the packets via the established IP tunnel; and reassembling the forwarded packets into a reassembled circuit call response for delivery by the home H.323 server. 9. The method as in claim 8, wherein the user's payment means comprises credit card information and wherein the step of identifying the user's payment means to the visited wireless network further comprises: establishing a Diffie-Hellman temporary shared secret between the user's mobile device and the visited wireless network; securely transmitting the user 's credit card information to the visited wireless service provider via the visited wireless network using the temporary shared secret; and verifying the validity of the user's credit card information by the visited wireless network. 10. The method as in claim 9, wherein the step of securely transmitting the user's credit card information further comprises retrieving previously stored credit card information within the user's mobile device. 11. The method as in claim 9, wherein the step of securely transmitting the user's credit card information further comprises the user entering credit card information into the user's mobile device. 12. A method to provide basic cellular call delivery service for a user having a mobile device and subscribing to a home wireless service provider serving a home wireless network, wherein the user roams to visit an area served by a visited wireless service provider serving a visited wireless network distinct and separate from the home wireless network, and wherein the user has a payment means to pay for the basic cellular call delivery service, the method comprising: establishing an Internet Protocol (IP) tunnel, having a first end and a second end, for conveying IP packets in both directions between the first end and the second end; delivering calls to the user's mobile device via the IP tunnel; collecting billing information from the visited wireless network by the visited wireless service provider; and billing the user by the visited wireless service provider responsive to the billing information collected and the user's identified payment means; wherein the step of establishing the IP tunnel further comprises the method: registering with a voice and data service provider's network to establish the first end of the IP tunnel; identifying the user's payment means to the visited wireless network; and registering with the visited wireless network to establish the second end of the IP tunnel, wherein the step of registering with a voice and data service provider's network to establish the first end of the IP tunnel further comprises: setting up call forwarding from the home wireless network to the voice and data service provider's network; and obtaining a Mobile IP shared secret from the voice and data service provider, wherein the step of setting up call forwarding from the home wireless network to the voice and data service provider's network further comprises: obtaining a telephone number for call forwarding from the voice and data service provider; providing a home H.323 server in the voice and data service provider's network; providing a Home Agent (HA) function within the home H.323 server; obtaining the IP address of the HA in the home H.323 server; and storing the IP address of the HA in the user's mobile device, wherein the step of registering with the visited wireless network to establish the second end of the IP tunnel within the user's mobile device further comprises: providing a visited H.323 server in the visited wireless network; providing a Foreign Agent (FA) function within the visited H.323 server; obtaining a dynamic IP address from the HA by the FA using Dynamic Host Configuration Protocol (DHCP); relaying the dynamic IP address from the HA via the visited wireless network to the user's mobile device; authenticating the connection by the user's mobile device using the Mobile IP shared secret; and establishing the IP tunnel by the user's mobile device. 13. The method as in claim 12, wherein the step of establishing the IP tunnel further comprises: updating a phone-number-to-IP-address table in the home H.323 server; updating a mobility binding table in the HA; and updating a IP-address-to-phone-number table in the visited H.323 server. 14. The method as in claim 12, wherein the step of delivering calls to the user's mobile device via the IP tunnel further comprises: conversion of a circuit call for delivery to packets by t