摘要:
A method of connecting an NFC reader to a plurality of NFC devices, the plurality of NFC devices comprising at least one NFC-A device and at least one RF barcode, the method comprising the steps of: detecting and logging the active and sleep intervals of the RF barcode when an RF field is switched on; and synchronizing the transmission and reception of data to, and from, the or each NFC-A device such that transmission and reception of data to, and from, the or each NFC-A device occurs only when the or each RF barcode is in a sleep interval.
摘要:
An NFC-B enabled listen device such as a smart mobile phone (1) is adapted by means of a controller implementing a control method to respond to a poll request signal (SENSB_REQ or ALLB_REQ) received from a read device (R). The read device may be another NFC-B enabled smart device such as another smart phone (R). In response to the poll request signal the listen device transmits a collision emulation signal. The collision emulation signal may be formed by adding and thereby simultaneously transmitting two or more poll response signals associated with two or more NFC-B applications running on the smart mobile phone (1). Alternatively the smart mobile phone (1) will send a synthesised pre-recorded collision emulation signal. Where the read device (R) is set to run the known NFC-B collision resolution process, the receipt of the collision emulation signal will provoke the read device (R) to increase the number of time slots available to receive poll response signal. According to the collision resolution process the increased number of slots is reported in a subsequent poll request signal. This enables a reliable, energy and time efficient resolution of all NFC-B applications active on the listen device without modification of the NFC-B read device.
摘要:
A method of simultaneously connecting a first NFC-enabled device in poll mode (52) with a plurality of second NFC-enabled listen mode devices (70, 72, 74), the method comprising: detecting the presence of the plurality of second NFC-enabled listen mode devices (70, 72, 74) and being characterised by: allocating to each of the detected second NFC-enabled listen mode devices (70, 72, 74), a separate logical channel (208) in an NFC controller interface (60) of the first NFC-enabled device (52). In each logical channel (208), a connection is suitably established and maintained and the instantaneous connection status of each of the detected second listen mode devices (70, 72, 74) is suitably monitored and/or recorded. A device-specific RF finite state machine (200) may be used for recording which NFC listen mode devices (70, 72, 74) are connected to the NFC interface (60) using which RF protocols (204). Likewise, a device-specific NCI finite state machine (206) is suitably used for recording which NFC listen mode devices (70, 72, 74) are allocated to which dynamic channels (208) of the NCI (60).
摘要:
In near field communication (NFC) a reader (PCD) (1), may be embodied in a smart mobile phone (1). The reader has a controller (2) controlling a transmitter 6 and a receiver (7) to transmit and receive signal in accordance with the NFC Forum and other specifications. The reader operates a method to resolve signal collisions between multiple NFC type A technology tags (i-vi), also known as PICCs or listen devices proximate when the reader generates an activating radio frequency field.
摘要:
An NFC enabled listening device (2) is capable of communication with an NFC enabled reading device in any of several NFC technologies, exemplified by NFC-A, NFC-B, NFC-F and NFC-V. To facilitate selection of the optimum communication technology, and to minimise time and energy consumption, the NFC enabled listening device (2) is provided with a plurality of control modules (4a-4d) each configured to decode only one of the several NFC technologies.
摘要:
An NFC reader is embodied in a mobile phone (200) and adapted to implement a tag/PICS/ listen device resolution method by an NFC resolution sub-system (207). In accordance with the method reader slot controller (204) starts the resolution process by setting only one time slot in a first poll response signal resolution cycle. Consequently all the tags (D1-D4) receiving a poll request signal from the reader (200) send the poll response signal in the one available time slot causing a collision if there is more than one NFC-B tag in range. The method then increases the number of time slots (N) to be deployed in a next resolution cycle. A collision counter (205) counts the number of time slots in each collision cycle in which a collision is detected. A calculator then calculates a new number of time slots (N) to deploy in a subsequent collision resolution cycle. The calculation is N=2 Noc where NoC is the counted number of collisions. Thus the number of time slots can both increase and decrease. The method enables the resolution of the last unresolved tag in range to be determined at the end of any resolution cycle in which no collisions are detected.
摘要:
A proximity coupling device (18, 30) is provided by a mobile phone and PICCs (tags (24, 25, 29)) of type 1 (24), type 2 (25) and type 4A/B (25). The tags (24, 25, 29) all respond to a poll request signal emitted by the proximity coupling device (18, 30) with poll response signals having a bit string characteristic of type 1 and type 2 tags (24, 25, 29) respectively. The proximity coupling device (18, 30) is responsive to reception of the bit strings to identify bit collisions in the bit strings emitted by different tags (24, 25, 29) within a radio frequency field (23) generated by the proximity coupling device (18, 30). The bit collisions enable the proximity coupling device (18, 30) to discriminate the presence of type 1 and type 2 tags (24, 25, 29) in the radio frequency field (23) and implement an efficient tag reading procedure.
摘要:
A method of connecting an NFC reader to a plurality of NFC devices, the plurality of NFC devices comprising at least one NFC-A device and at least one RF barcode, the method comprising the steps of: detecting and logging the active and sleep intervals of the RF barcode when an RF field is switched on; and synchronizing the transmission and reception of data to, and from, the or each NFC-A device such that transmission and reception of data to, and from, the or each NFC-A device occurs only when the or each RF barcode is in a sleep interval.