Systems, methods, and devices for access control

A reader comprising:

• a first communication interface for wireless communication;
• a processor;
• and
• a memory comprising instructions that when executed by the processor cause the processor to:
• establish, using the first communication interface, a link with a credential device when the credential device enters an engagement range of the reader, the credential device comprising credential data, wherein the engagement range is determined by periodic assessment of an environment surrounding the reader;
• receive from the credential device, over the link, the credential data using a first communication protocol with the credential device;
• verify that the credential device is valid based on the credential data;
• mark the credential device as valid and track a location of the credential device relative to the reader using a second communication protocol with the credential device different than the first communication protocol;
• and
• make or delay an access control decision for the credential device based on the location of the credential device.