Abstract:
To provide a better solution in these areas compared to existing standard, “IEEE
802.11ah HaLow” was standardized by making amendments to IEEE 802.11 in 2016. It is the
first sub 1 GHz WLAN standard with characteristics of multiband multimode of operation,
ranging from 1 MHz to 16 MHz up to 10 modes in each respectively, improved physical and
link layer, long-range and energy efficient communications. In the proposed communication
scenario, Multiple Unmanned Aerial Vehicles (UAVs) are communicating with Ground
Control Station (GCS). All of the UAVs have a Bi-directional communication link with the
GCS and among themselves creating a mesh network. Each of the UAV transmits video
surveillance data to the GCS for processing along with control messages but all the UAVs
share only control messages among themselves. Multiple user scenario required multiple
access system that allows multiples users to transmit data without any interference. TDMA,
FDMA and CDMA are the options available for channelization purpose and CDMA is
selected due to better performance (allowing multiple users to transmit data simultaneously
utilizing the complete band without any ISI) as compared to FDMA and TDMA. Multicarrier
CDMA for IEEE 802.11ah is simulated for performance curves and data rates. Control data
has smaller size as compared to video transmission data but more importance i.e. control data
provides a reliable connection between different entities in the scenario. Without reliable
connection there can be no data transmission. As different data rates are required for control
data and video surveillance data, multicode (multiple CDMA spreading codes) concept is
proposed in this scenario to improve the data rates suitable for multiple links. Multimode
Multiband in Multicarrier CDMA provided with many modes with different range of data
rates. A comparison based on similar data rates and best performance was made with reduced
the modes to few that were simulated for Multicode Multicarrier CDMA in AWGN (Additive
White Gaussian Noise) for IEEE 802.11ah. Complete performance analysis and data rates
comparison for IEEE 802.11ah and both of the proposed methodologies are presented along
with future work
