Methods and apparatuses relating to activation signals for tag devices

An activator device comprising:

• means for transmitting at least a first activation signal and a second activation signal,
• the first activation signal comprising a first charging portion for charging a tag device, a first backscatter portion for backscattering by the tag device and a first security portion between the first charging portion and the first backscatter portion modulated to carry a first code for detection by the tag device,
• the second activation signal comprising a second charging portion for charging the tag device, a second backscatter portion for backscattering by the tag device and a second security portion between the second charging portion and the second backscatter portion modulated to carry a second code for detection by the tag device,
• wherein the second code immediately follows the first code in a predetermined sequence of codes that is stored at the tag device.

A session control entity comprising means for transmitting to an activator device configuration information indicative of:

• a first code that is to be modulated on to a first security portion of a first activation signal that is to be transmitted by the activator device to a tag device;
• and
• a second code that is to be modulated on to a second security portion of a second activation signal that is to be transmitted by the activator device to the tag device,
• wherein the second code immediately follows the first code in a predetermined sequence of codes that is stored at the tag device.

A method comprising:

• receiving, at a tag device, a series of activation signals, each comprising a charging portion for charging the tag device, a backscatter portion for backscattering by the tag device and a security portion between the charging portion and the backscattering portion modulated to carry a respective code;
• detecting, by the tag device, the codes carried by the activation signals;
• comparing, by the tag device, the detected codes with codes of a predetermined sequence of codes that is stored at the tag device;
• refraining, by the tag device, from backscattering information in response to the activation signals until a subsequence of n consecutive codes from the predetermined sequence of codes has been detected in the series of activation signals, wherein n is at least two;
• and
• in response to a determination that a subsequence of n consecutive codes from the predetermined sequence of codes has been detected in the series of activation signals, backscattering, by the tag device, information related to the tag device using the backscatter portion of an activation signal of the series of activation signals in which the nth of the n consecutive codes is detected.

A method comprising:

• transmitting, by an activator device, at least a first activation signal and a second activation signal,
• the first activation signal comprising a first charging portion for charging a tag device, a first backscatter portion for backscattering by the tag device and a first security portion between the first charging portion and the first backscatter portion modulated to carry a first code for detection by the tag device,
• the second activation signal comprising a second charging portion for charging the tag device, a second backscatter portion for backscattering by the tag device and a second security portion between the second charging portion and the second backscatter portion modulated to carry a second code for detection by the tag device,
• wherein the second code immediately follows the first code in a predetermined sequence of codes that is stored at the tag device.

A method comprising:

• transmitting, by a session control entity and to an activator device, configuration information indicative of:
• a first code that is to be modulated on to a first security portion of a first activation signal that is to be transmitted by the activator device to a tag device;
• and
• a second code that is to be modulated on to a second security portion of a second activation signal that is to be transmitted by the activator device to the tag device,
• wherein the second code immediately follows the first code in a predetermined sequence of codes that is stored at the tag device.