Transmission time frame structure for time division duplex communication

A Time Division Duplex (TDD) two-way communication device configured to structure a transmission time frame for TDD two-way communication on frequency bands that are extendable below 6 GHz, the transmission time frame being assigned for a direction of communication and being temporally divided into a plurality of transmission symbols, wherein a separating guard band separates the transmission time frame from a second transmission time frame, said device comprising a processor configured to:

• assign a first fraction of a frequency bandwidth for a selected transmission symbol from the plurality of transmission symbols to an opposite direction of communication, wherein the first fraction is an inner portion of the frequency bandwidth for the selected transmission symbol, wherein the first fraction includes data acknowledgement information, and wherein a frequency band for the transmission time frame, which includes the selected transmission symbol, is extendable below 6 GHz;
• assign a second fraction within the frequency bandwidth for the selected transmission symbol as a first guard band;
• assign a third fraction within the frequency bandwidth for the selected transmission symbol as a second guard band, wherein the first guard band and the second guard band are positioned on opposite sides of the first fraction in the selected transmission symbol;
• cause the second guard band to be at a position that is adjacent to the separating guard band, resulting in two separate guard bands being positioned immediately next to one another;
• and
• as a result of the second guard band being adjacent to the separating guard band, resulting in a combination of the second guard band and the separating guard band providing separation between communications, and as a result of the first guard band independently providing separation between communications transmitted in opposing directions, configuring a bandwidth of the first guard band to be larger than a bandwidth of the second guard band, wherein:
• the selected transmission symbol is configured to include one or more internally positioned guard bands and one or more externally positioned guard bands,
• the one or more externally positioned guard bands being located on a first terminal end or a second terminal end of the selected transmission symbol,
• the one or more internally positioned guard bands being bounded on either side by another guard band that is included in the selected transmission symbol or a message that is included in the selected transmission symbol, and
• in response to one of the one or more externally positioned guard bands having a position that is next to another guard band that is not a part of the selected transmission symbol, the one or more externally positioned guard bands are configured to be smaller than the one or more internally positioned guard bands.