802.11ah Packet Formats
What is a packet format in 802.11ah?
It is the defined structure of bits and fields used to encapsulate data for transmission at the MAC and PHY layers.
How does 802.11ah packet format differ from other 802.11 standards?
802.11ah adapts packet fields to support long-range, low-power IoT communications in the sub-1 GHz band.
What are the main components of an 802.11ah MAC frame?
Frame Control, Duration/ID, Address fields, Sequence Control, QoS Control, and Frame Check Sequence (FCS).
What is the purpose of the Frame Control field?
It specifies the frame type, subtype, protocol version, and control flags for frame handling.
How many address fields are in an 802.11ah MAC frame?
Typically four address fields to identify sender, receiver, source, and destination.
Does 802.11ah support fragmentation in packet formats?
Yes, it allows fragmentation and reassembly to support large data transmissions over unreliable links.
What role does the Sequence Control field play?
It tracks packet order and helps detect duplicates.
What types of frames are defined in 802.11ah?
Management frames, control frames, and data frames.
What are management frames used for?
They manage connection setup, maintenance, and teardown, such as Beacon, Probe Request, and Authentication frames.
What are control frames in 802.11ah?
Frames like ACK, RTS, and CTS that help regulate access and acknowledge receipt.
How does 802.11ah handle QoS in packet formats?
Through the QoS Control field, enabling traffic prioritization.
What is the Frame Check Sequence (FCS)?
A CRC-based field used for error detection in frames.
Does 802.11ah include any specific fields for power saving?
Yes, fields in management frames help coordinate sleep and wake cycles.
Are there any changes in the PHY layer packet format for 802.11ah?
Yes, the PHY layer adapts the preamble and header for sub-1 GHz operation and extended range.
How is the payload carried in 802.11ah packets?
The payload contains the MAC Service Data Unit (MSDU) encapsulated in the frame body.
What mechanisms ensure interoperability in packet formats?
Standardized frame formats and control fields allow devices from different vendors to communicate.
How does 802.11ah optimize packet formats for low power?
By reducing overhead and allowing aggregation to minimize transmissions.
Where can detailed 802.11ah packet format specifications be found?
In the official IEEE 802.11ah standard documentation under MAC and PHY layer sections.
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