# US 2014/0192642 A1 · Mobile device with cellular-wlan offlaod using passive load sensing of wlan > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192642 A1 - Document ID: US20140192642A1 - Status: Published application - Kind: A1 - Application number: 14/149,390 - Filed: 2014-01-07 - Published: 2014-07-10 - Earliest claimed: 2013-01-08 - Assignees: Broadcom Corporation - Applicants: Broadcom Corporation - Inventors: Kamesh MEDAPALLI - Web page: https://patentgrep.com/patent/US20140192642A1 ## CPC - H04W 48/18: Selecting a network or a communication service - H04W 28/02: Traffic management, e.g. flow control or congestion control - H04W 28/0205: {at the air interface (dynamic wireless traffic scheduling H04W72/12)} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract Apparatus and methods are provided for switching between a wireless local area network (LAN) and a cellular network for a user equipment's (UE) data communication by passively sensing the load on the wireless LAN. A method is disclosed that includes detecting an access point associated with a wireless LAN and receiving packets that are transmitted by other devices that are using the wireless LAN. The method can further include examining the received packets to estimate a data load of the wireless LAN and selecting between the wireless LAN and a cellular network based on the estimated data load. ## Claims ### Claim 1 A method of signal processing in a user equipment (UE) to select between a wireless local area network (LAN) and a cellular network for data transmission, comprising: detecting, by the UE, an access point associated with the wireless LAN; receiving, by the UE, packets that are transmitted by other devices that are using the wireless LAN; examining, by the UE, the received packets to estimate a data load of the wireless LAN; and selecting between the wireless LAN and the cellular network based on the estimated data load. ### Claim 2 (depends on 1) The method of claim 1, further comprising: comparing the estimated data load of the wireless LAN with a corresponding parameter of the cellular network; and selecting one of the wireless LAN or the cellular network for the data transmission based on the comparison. ### Claim 3 (depends on 2) The method of claim 2, further comprising: determining a difference between the estimated data load of the wireless LAN and the corresponding parameter of the cellular network; comparing the difference with a threshold; and selecting one of the wireless LAN or the cellular network for the data transmission based on the comparison of the difference and the threshold. ### Claim 4 (depends on 1) The method of claim 1, wherein the estimating a data load comprises: determining a number of active users on the wireless LAN based on a number of different media access control (MAC) addresses identified for the received packets; and determining data rates of the active users based on packet headers of the received packets associated with the active users. ### Claim 5 (depends on 4) The method of claim 4, wherein the estimating a data load further comprises: determining a prospective data rate of the UE if the UE were to access the wireless LAN; and estimating an expected throughput for the UE if the UE were to access the wireless LAN, based on the determined prospective data rate of the UE and the data rates of the active users. ### Claim 6 (depends on 5) The method of claim 5, wherein the estimating a data load further comprises: determining an expected delay of the UE if the UE were to access the wireless LAN based on the estimated expected throughput for the UE. ### Claim 7 (depends on 4) The method of claim 4, wherein the determining data rates of the active users comprises determining data rates of the active users by examining preamble/PLOP headers of 802.11 packets associated with the active users. ### Claim 8 (depends on 5) The method of claim 5, wherein the determining a prospective data rate of the UE is based on a detected RSSI associated with the access point. ### Claim 9 (depends on 1) The method of claim 1, further comprising: determining a quality of service provided the by wireless LAN; comparing the determined quality of service with a quality of service required by an application supported by the UE; and selecting one of the wireless LAN or the cellular network for the data transmission based on the comparison. ### Claim 10 (depends on 1) The method of claim 1, further comprising: transmitting data, by the UE, on the selected network; and periodically updating the estimated data load, and changing networks if warranted. ### Claim 11 A user equipment (UE), comprising: a radio transceiver configured to transmit signals to a wireless local area network (LAN); and a control logic configured to: detect an access point associated with the wireless LAN; receive packets that are transmitted by other devices that are using the wireless LAN; examine the received packets to estimate a data load of the wireless LAN; and select between the wireless LAN and a cellular network based on the estimated data load. ### Claim 12 (depends on 11) The UE of claim 11, wherein the control logic is further configured to; compare the estimated data load of the wireless LAN with a corresponding parameter of the cellular network; and select one of the wireless LAN or the cellular network for the data transmission based on the comparison. ### Claim 13 (depends on 12) The UE of claim 12, wherein the control logic is further configured to: determine a difference between the estimated data load of the wireless LAN and the corresponding parameter of the cellular network; compare the difference with a threshold; and select one of the wireless LAN or the cellular network for the data transmission based on the comparison of the difference. ### Claim 14 (depends on 11) The UE of claim 11, wherein the estimating a data load comprises: determining a number of active users on the wireless LAN based on a number of different media access control (MAC) addresses identified for the received packets; and determining data rates of the active users based on packet headers of the received packets associated with the active users. ### Claim 15 (depends on 14) The UE of claim 14, wherein the estimating a data load further comprises: determining a prospective data rate for prospective data transmissions of the UE over the wireless LAN; and estimating an expected throughput for the prospective data transmissions, based on the determined prospective data rate and the data rates of the active users. ### Claim 16 (depends on 15) The UE of claim 15, wherein the estimating a data load further comprises: determining an expected delay for the data transmissions if the UE were to access the wireless LAN based on the estimated expected throughput for the data transmissions. ### Claim 17 (depends on 14) The UE of claim 14, wherein the determining data rates of the active users comprises determining data rates of the active users by examining preamble/PLCP headers of 802.11 packets associated with the active users. ### Claim 18 (depends on 15) The UE of claim 15, wherein the determining a prospective data rate of the UE is based on a detected RSSI associated with the access point. ### Claim 19 (depends on 11) The UE of claim 11, wherein the control logic is further configured to: determine a quality of service provided the by wireless LAN; compare the determined quality of service with a quality of service required by an application supported by the UE; and select one of the wireless LAN or the cellular network for the data transmission based on the comparison. ### Claim 20 (depends on 11) The UE of claim 11, wherein the control logic is further configured to: initiate transmission of data on the selected network; and periodically update the estimated data load, and change networks if warranted.