Wireless identification systems and protocols

In a system for monitoring location of tags, the system comprising at least two of a monitor, a locator, and a tag, a method performed by at least one of the monitor, the locator, and the tag for transmitting a message, the message comprising a first group of slots and a second group of slots, the method comprising:

• generating a first part of a message by inserting a high or low signal in each slot within a first group of slots, such that the high signals are separated in time by a minimum number of slots;
• transmitting the first part of the message;
• and
• transmitting a second part of the message, wherein the second part's high and low signals within a second group of slots are inverse in magnitude from those in the first part.

In a system for monitoring location of tags, the system comprising at least two of a monitor, a locator, and a tag, a method performed by at least one of the monitor, the locator, and the tag for transmitting a message, the message comprising a first group of slots and a second group of slots, the method comprising:

• generating a first part of a message by inserting high or low signal in each slot within a first group of slots, such that the high signals are separated in time by a minimum number of slots;
• transmitting the first part of the message;
• and
• transmitting a second part of the message, wherein the second part's high and low signals within a second group of slots are inverse in time and magnitude from those in the first part.

A system for monitoring location of tags, the system comprising a monitor, a plurality of locators, and a plurality of tags, communication from a sender, being at least one of the monitor, a particular locator, and a particular tag, comprising a message that includes a first group of slots and a second group of slots, the sender comprising:

• means for generating a first part of a message by inserting a high or low signal in each slot within a first group of slots, such that the high signals are separated in time by a minimum number of slots;
• means for transmitting the first part of the message;
• and
• means for transmitting a second part of the message, wherein the second part's high and low signals within a second group of slots are in reverse order from those in the first part.

A system for monitoring location of tags, the system comprising a monitor, a plurality of locators, and a plurality of tags, communication from a sender, being at least one of the monitor, a particular locator, and a particular tag, comprising a message that includes a first group of slots and a second group of slots, the sender comprising:

• means for generating a first part of a message by inserting a high or low signal in each slot within a first group of slots, such that the high signals are separated in time by a minimum number of slots;
• means for transmitting the first part of the message;
• and
• means for transmitting a second part of the message, wherein the second part's high and low signals within a second group of slots are inverse in magnitude from those in the first part.

A system for monitoring location of tags, the system comprising a monitor, a plurality of locators, and a plurality of tags, communication from a sender, being at least one of the monitor, a particular locator, and a particular tag, comprising a message that includes a first group of slots and a second group of slots, the sender comprising:

• means for generating a first part of a message by inserting high or low signal in each slot within a first group of slots, such that the high signals are separated in time by a minimum number of slots;
• means for transmitting the first part of the message;
• and
• means for transmitting a second part of the message, wherein the second part's high and low signals within a second group of slots are inverse in time and magnitude from those in the first part.