# IEEE 802.11 ah: A Technology to Face the IoT Challenge
## 3 Comparative Analysis of IEEE 802.11 ah with Previous IEEE 802.11 Amendments
### Comparison of IEEE 802.11 Amendments Based on MAC Features
#### 3.2.Throughput and Range Characterization of IEEE 802.11 Amendments
[13], who utilize a Bit Error Rate (BER) model for different MCS, we use the minimum receiver sensitivity established in the proposed IEEE 802.11 ah amendment (cf. Tables 23-31--Receiver minimum input level sensitivity in [2]). That is, for each distance and propagation model considered, we assume the transmitter is using the fastest available MCS, the minimum sensitivity of which is larger than the received power at that distance. For that reason Figures 2 and 3 show a stepped relationship between throughput and coverage range. As expected, using the most robust MCS leads to increased coverage and more reliable communication, while employing higher order MCS, the benefit of the higher data rate in the communication scenario can be observed (cf. Figures 2 and 3). The use of sub 1 GHz frequency band, together with the new and more robust modulation MCS10 provide benefit to IEEE 802.11 ah in achieving the long range feature, i.e., IEEE 802.11 ah amendment can operate under macro deployment scenario and can achieve a coverage range of up to 1500 m. The same PHY configuration can reach up to 900 to 1100 m in different indoor scenarios. Hence, in terms of coverage, there is seven-fold improvement using IEEE 802.11 ah with the most robust MCS with respect to best sub-6 GHz amendment result (IEEE 802.11 ac, 20 MHz, with 1 SS). Furthermore, the improvement obtained by the new MCS10 in the IEEE 802.11 ah case is around 15% for distance reached in macro deployment in comparison with the lowest MCS (MCS0) with 1 SS, and around 20% in indoor case. Besides, the use of more than 1 SS improves the throughput up till 95% when employing four SS, but in turn reduces the coverage range considerably. It is also important to highlight the fact that improving range results in throughput performance decrease. However, the throughput achieved by the IEEE 802.11 ah in the limit of its coverage can still reach the 100 kbps, which can be enough for most of IoT applications. It is also worth mentioning that a higher throughput performance can be obtained for IEEE 802.11 ah employing two 8 MHz or four 4 MHz channels instead of one 16 MHz channel. First, note that the use of larger CBW improves the transmission efficiency since it allows the use of a larger proportion of data subcarriers (pilot, guard subcarriers are the same regardless of the CBW used). However, the required receiver minimum input sensitivity also increases by using larger CBW, thus a better signal quality is needed at the receiver to complete a successful reception. In this way, for long distances, it results in a more profitable practice to use, for example, 16 channels of 1 MHz CBW instead of 1 channel of 16 MHz CBW; with high signal quality in reception, the larger bandwidth becomes a better option due to the better proportion of data/pilot OFDM carriers. Figure 2: Macro deployment A-MPDU throughput vs. coverage range in IEEE 802.11: (**a**) shows the throughput using 1 SS for 802.11n and 802.11 ac; (**b**) exposes the throughput for 802.11 ah in 1, 2, 4, 8, 16 MHz CBW with 1 SS, highlighting the new MCS10 with 1 SS; (**c**) depicts the throughput using 4 and 8 SS for 802.11n and 802.11 ac, respectively; (**d**) highlights the throughput for 802.11 ah using 4 SS.