# IEEE 802.11 ah: A Technology to Face the IoT Challenge
## 4 IoT Applications
### Meeting the Requirements of IoT Applications
According to Table 4, the maximum number of simultaneous transmitters at the largest distance is 55 and, therefore, we could admit up to 4200 associated devices; however, note that with 4200 transmitters, the probability of having 56 or more simultaneous contenders (i.e., probability of having congestion) is relatively high, at 30%. Therefore, in order to reduce congestion, we suggest that the number of admitted stations is reduced to 80% or less (e.g., 3300); in such case, the probability of congestion is reduced to less than 2% (assuming that stations behave as independent ON-OFF state machines, the number of simultaneous transmitters and congestion probability can be obtained by treating the system as an _M/M/C_, where \(C\) corresponds to the number of supported devices reported in Tables 4 and 5). It is also apparent, how in circumscribed cases (backhaul, firmware, EHR, video and image applications), the use of frame aggregation is a key enabler, necessary to meet throughput requirements. Finally, we would like to highlight the fact that most of the technologies presented in Table 1, do not meet throughput requirements of most of the IoT applications considered in this Section 4 when providing enough coverage and supported users, or fail to provide a decent coverage when meeting throughput requirements. Note that, in comparison with other notable technologies contenders for IoT, which offer data rates from 1 kbps up to 1 Mbps, IEEE 802.11 ah presents a wider range of available operating rates that go from 150 kbps up to 346 Mbps. \begin{table} \begin{tabular}{c c c|c c c c c} \hline \hline  & **Application** & **Description** & **Average Payload** & **Average Aggregate** & **Supported Devices at** & **Supported Devices at** & **Supported Devices at** \\  & & **Size (Byte)** & **Data Rate (Kplex)** & **-12 (Out/load)** & **-500 (B/out/load)** & **-250 (B/out/load)** & **-250 (B/out/load)** \\ \hline \multirow{4}{*}{
\begin{tabular}{c} Permanent \\ connectivity \\ applications \\ \end{tabular} } & Home/Building automation & 100 & 15-30 & 1250 & 2100 & 2500 \\ \cline{2-7}  & On-demand meter reading & & 100 & 40-180 & 250 & 1000 & 1200 \\ \cline{2-7}  & Distribution Automation & Sensitive delay applications, & 150 & 60-80 & 55 & 300 & 400 \\ \cline{2-7}  & Electric service requirement & & 50-150 & 30-00 & 725 & 2000 & 2100 \\ \cline{2-7}  & Service on/off switch & & & 25 & 5-10 & 1600 & 2400 & 2600 \\ \cline{2-7}  & Security (phone, alarms) & & industrial facilities, smart dies & 100 & 40-180 & 250 & 1000 & 1150 \\ \cline{2-7}  & Background/over-meta networks * & applications, etc. & & 1500 & 240-100 & 1 & 6 & 17 \\ \cline{2-7}  & Parking Availability & & 100 & 40-180 & 250 & 1000 & 1150 \\ \cline{2-7}  & Street traffic & & 100 & 40-180 & 250 & 1000 & 1150 \\ \cline{2-7}  & Multi-interval meter reading & Delay-tolerant where data is & 100 & 40-180 & 250 & 1000 & 1150 \\ \cline{2-7}  & Finawase Updates * & collected infrequently & 1500 & 45-250 & 400 & 1800 & 2500 \\ \cline{2-7} Event-based & Cartage Collection & multiple time per day & 100 & \textless{}1 & 4200 & 5000 & 5300 \\ \cline{2-7}  & Lighting Control & applications, including all & 100 & \textless{}1 & 4200 & 5000 & 5300 \\ \cline{2-7}  & Green zone management & requiring permanent connectivity & 100 & \textless{}1 & 4200 & 5000 & 5300 \\ \cline{2-7}  & Environmental Control & such as scheduled reporting of & 64 & \textless{}1 & 4200 & 5000 & 5300 \\ \cline{2-7}  & Utility infrastructure & bulk measurements. & 100 & \textless{}1 & 4200 & 5000 & 5300 \\ \hline \end{tabular}   
* The numbers of the backhaul application are provided assuming frame aggregation, with which IEEE 802.11 ah is capable of meeting the minimum throughput requirements of the backhaul application. Note that wireless backhaul application consists in a network of point-to-point links, where the required number of supported STAs per link is 1 (plus the AP).