Rapid discovery of closest base station in 5G and 6G networks
A new user seeking a base station to join must first implement a grueling series of complex steps, which may be especially challenging for the majority of devices expected in next-generation 5G and 6G systems. If the user has a real emergency, such as an imminent traffic collision, then the time wasted in locating (“discovering”) a nearby base station and finally logging on may make the difference between life and death. Disclosed herein are procedures for new users to transmit a “hailing” message on an allocated frequency that multiple base stations continuously monitor. The base stations can then reply at a standard amplitude, so that the new user can determine which base station is closer (or provides the best signal reception) according to the received amplitude. In addition, the reply messages can include a characteristic frequency of the replying base station, such as its entry frequency.
1. A base station of a wireless network, the base station containing non-transitory computer-readable media containing instructions that, when executed by a computing environment, cause a method to be performed, the method comprising;
determining a predetermined hailing frequency allocated for user devices to transmit hailing messages;
receiving a broadcast hailing message from a prospective user device on the predetermined hailing frequency, wherein the broadcast hailing message indicates that a reply message is requested from base stations that can accept a new user;
determining that the base station can accept a new user;
measuring an amplitude of the broadcast hailing message as received by the base station;
calculating a delay time inversely related to the amplitude, the delay time not exceeding a predetermined maximum delay time; and
after the delay time, transmitting, according to a predetermined transmission power level, a reply message to the user device on the predetermined hailing frequency.
2. The base station of claim 1 , the method further comprising:
if the base station detects a communication from another base station to the user device during the delay time, waiting a predetermined listen-before-talk (LBT) interval, and then, if no further transmissions are detected during the LBT interval, transmitting the reply message to the user device on the predetermined hailing frequency.
3. The base station of claim 1 , wherein the reply message specifies a particular frequency, or an offset indicating the particular frequency.
4. The base station of claim 3 , wherein the particular frequency is related to a physical broadcast channel or a random access channel of the base station.
5. The base station of claim 1 , wherein the reply message indicates a first frequency and a second frequency different from the first frequency.
6. The base station of claim 1 , wherein the reply message specifies system information of the base station.
7. A wireless network comprising a first base station in signal communication with a plurality of user devices, the first base station configured to:
a) determine a maximum traffic capacity of the first base station;
b) determine a predetermined limit less than 1;
c) determine a hailing frequency allocated for user devices to transmit discovery messages to base stations;
d) measure a fraction comprising a current traffic level of the first base station divided by the maximum traffic capacity of the first base station;
e) if the fraction is below the predetermined limit, receive a hailing message broadcast by a prospective user device;
f) measure a value related to the hailing message;
g) communicate the value and the fraction to a network administrative entity; and
h) upon receiving, from the network administrative entity, an instruction to accept the prospective user device, transmit a reply message to the prospective user device.
8. The wireless network of claim 7 , wherein the value comprises at least one of:
a) an amplitude of the as-received hailing message;
b) a power level of the as-received hailing message;
c) a signal quality of the as-received hailing message; and
d) a signal-to-noise ratio of the as-received hailing message.
9. The wireless network of claim 7 , wherein the value comprises a distance between the prospective user device and the first base station.
10. The wireless network of claim 7 , further comprising:
a) while the fraction exceeds the predetermined limit, determining whether a hailing message, received on the hailing frequency, is an emergency message;
b) if the hailing message is not an emergency message, ignoring the hailing message;
c) if the hailing message is an emergency message, determining whether another base station has responded to the emergency message; and
d) if no other base station has responded to the emergency message, transmitting a reply message to the prospective user device.
11. The wireless network of claim 7 , further comprising:
a) if the hailing message indicates that the prospective user device has not received an SSB (synchronization signal block) message of the first base station, transmitting, in the reply message, system information of the first base station.