Semaphore Messages for Rapid 5G and 6G Network Selection
Base stations may transmit periodic “semaphore” signals on a shared semaphore channel, so that user devices can connect to whichever proximate base station provides the best reception. Each semaphore message may include a frequency of an entry channel of that base station, so that the user device can connect to that base station's entry channel, receive system information, and register with that selected base station. In addition, each base station may also transmit semaphore messages periodically on its own random access channel, thereby enabling the user devices to adjust their frequency and timing before contacting the base station, for greatly improved reception. The procedures disclosed herein may enable rapid access to 5G and 6G networks, within the capabilities of low-cost wireless devices, and may thereby enable a wide range of otherwise unfeasible cost-constrained applications.
1 . A base station of a wireless network, wherein:
the base station is configured to periodically transmit a semaphore message on a semaphore frequency, the semaphore message indicating a second frequency comprising a frequency of an entry channel of the base station, the entry channel providing system information associated with the base station; and
the base station is further configured to adjust a time of transmitting the semaphore message to avoid interfering with other semaphore messages transmitted by other base stations on the semaphore frequency.
2 . The base station of claim 1 , wherein the semaphore message is transmitted according to 5G or 6G technology.
3 . The base station of claim 1 , wherein the entry channel is a PBCH (physical broadcast channel) of the base station and the system information is a SSB (synchronization signal block) of the base station.
4 . The base station of claim 1 , wherein the entry channel is a random access channel of the base station and the system information is a temporary identification code.
5 . The base station of claim 4 , further configured to receive a message from a user device on the random access channel, and to responsively transmit the system information to the prospective user device on the random access channel.
6 . The base station of claim 1 , further configured to communicate with the other base stations and to cooperatively schedule the semaphore messages to avoid message collisions.
7 . The base station of claim 1 , further configured to provide a gap between adjacent semaphore messages, the gap sufficient to prevent adjacent semaphore messages from overlapping.
8 . The base station of claim 1 , wherein the semaphore message indicates a frequency difference equal to the frequency of the entry channel minus the first frequency.
9 . The base station of claim 1 , wherein the semaphore message specifies a number of subcarrier spacings.
10 . The base station of claim 1 , wherein the frequency of the entry channel comprises a subcarrier count, such that the frequency of the entry channel equals a constant plus a product of the subcarrier count times a subcarrier spacing in kilohertz.
11 . A wireless user device configured to:
receive, on a particular frequency or frequency band, a plurality of semaphore messages, each semaphore message transmitted by a different base station;
measure a property of each of the received semaphore messages;
select one of the semaphore messages according to a criterion based at least in part on the measured property; and
communicate with the base station that transmitted the selected semaphore message;
wherein the communicating comprises receiving system information from the base station or transmitting a request to register with the base station.
12 . The device of claim 11 , wherein the property comprises a signal amplitude or a power level or a signal quality of each as-received semaphore message, respectively.
13 . The device of claim 11 , further configured to determine, from the selected semaphore message, a frequency or frequency offset.
14 . The device of claim 11 , wherein the system information message is received on a frequency indicated by the selected semaphore message.
15 . The device of claim 11 , wherein the system information comprises a SSB (synchronization signal block) message or portions thereof.
16 . The device of claim 11 , further configured to transmit, on a frequency determined from the selected semaphore message, an entry request message comprising a random access preamble or a request for a temporary identification code.
17 . A method for a base station of a wireless network to communicate with a user device, the method comprising:
receiving or attempting to receive, during a predetermined interval, a wireless signal on a random access channel of the base station;
then, if no wireless signal is received during the predetermined interval, broadcasting a semaphore message on the random access channel, the semaphore message comprising at least a demodulation reference;
then receiving, from the user device, on the random access channel, an entry request message, the entry request message comprising at least a request to register with the base station and an identification code of the user device; and
then transmitting, on the random access channel, a welcome message comprising at least system information of the base station.
18 . The method of claim 17 , wherein the predetermined interval is at least one symbol period in duration.
19 . The method of claim 17 , wherein the entry request message is a random access preamble or an introductory message that includes a MAC (media access control) address of the user node.
20 . The method of claim 17 , wherein the welcome message further includes a temporary identification code comprising a C-RNTI (cell radio network temporary identification) code or a TC-RNTI (temporary cell radio network temporary identification) code.