Jiri is passionate about mobility ranging from Wi-Fi to folding bikes;-) He is a Wi-Fi Technical Solutions Architect at Cisco UK, proud member of the Cisco Live Network Operations Center deployment team, and WLAN Pi development team. If he is not working, he is most likely riding his Brompton bike.
All opinions are my own, not Cisco's.
Cisco’s Wi-Fi 6E outdoor CW9163E access point requires an external antenna. It has no built-in Wi-Fi antenna. The antenna is a separate purchase and is not included.
You can choose between either omnidirectional dipoles (make sure you order 4 of them), which we covered here, or an external directional patch antenna CW-ANT-D1-NS-00. That’s what we are going to talk about today.
CW-ANT-D1-NS-00 is a 2×2 self-identifying antenna (SIA). The AP detects its presence, model and gain automatically. No more manual antenna configuration needed on your part anymore, yay!
Here is what’s in the box.
After opening all little paper bags you will find these accessories.
Coaxial cable length is about 60 cm and it uses N-type connectors. On the antenna side, all coax cables are permanently attached and are not removable.
The thickest part of the N-type connector measures about 2 cm.
Don’t judge my cable management, please. Also, colour of the AP and antenna is the usual “Cisco outdoor AP grey”. White balance in these two photos is slightly misleading, my bad.
The cable length allows you to achieve about 20 cm distance between the AP and the antenna.
Ultimately, this is how the final setup looks like.
Note: For official Cisco guidance and information, please refer to the Cisco.com data sheet and deployment guide
Cisco’s Wi-Fi 6E outdoor CW9163E access point is an external antenna only model. It requires either 4 omnidirectional dipole antennas CW-ANT-O1-NS-00, or a directional CW-ANT-D1-NS-00 antenna (note the “D”) which we covered in this post.
The CW-ANT-O1-NS-00 antenna ships in a little recycled paper bag and it includes a single antenna. Please make sure you order this CW-ANT-O1-NS-00 SKU four times and connect antennas to all 4 N-type ports.
Note: If you have no plans to use 6 GHz, or can’t use 6 GHz outdoors in your country, scroll down. You might potentially get away with 2 antennas.
Here is a detail of the label.
If you are wondering what its dimensions are, here is a small UK banana for scale 😊
Joking aside, the antenna is about 23 cm long.
And its thickest point measures 2,8 cm.
Finally, here is the AP with all 4 antennas attached.
The whole set is about 65 cm tall.
These dipoles are self-identifying antennas (SIA) and the AP automatically detects their presence, model, and gain. In my setup I have 4 dipoles connected to the AP and since I am in the UK (where we don’t permit 6 GHz outdoor use yet), my 6 GHz radio has no channel assigned, and it is disabled in software on access points installed in Europe as of April 2025.
No plans for 6 GHz? No problem.
If your country has no plans to enable 6 GHz outdoors, you could only populate the bottom 2 antennas. These are connected to the 2.4 GHz and 5 GHz radios. The top 2 N-type ports marked 6 GHz technically don’t need an antenna if you don’t plan to use them. But we must protect them from weather by N-type connector caps. Simply order CW-ACC-KIT1-00 accessory kit which includes 4 caps as well as other accessories.
Install the connector caps on 6 GHz ports A and B. Please note I am using compatible caps I already owned. The official Cisco ones might look slightly differently.
Let’s have a quick look from the front.
Just keep in mind that if you change your mind and want to use 6 GHz later, you will have to purchase the missing 2 antennas, remove the caps, and connect the additional antennas. So, expect some extra installation efforts. It might well make your life easier if you attach all 4 antennas from the get-go.
As expected, the AP will detect the bottom 2 antennas serving 2.4 GHz and 5 GHz bands but not the top two 6 GHz antennas.
From physical footprint perspective, CW9163E equipped with the bottom 2 antennas is nearly as tall as MR76/MR86 with all 4 antennas attached.
Note: For official Cisco guidance and information, please refer to the Cisco.com data sheet and deployment guide.
It is the latest modulation technique that allows the access point and Wi-Fi client to send even more data over the air than ever before. Effectively, it adds 2 new MCS indexes 12 and 13 and unlocks faster data rates.
4096-QAM MCS indexes, credit to http://mcsindex.net
Achieving it is challenging as it requires very high Signal to Noise Radio (SNR) – that’s very strong signal and low noise. So in practical terms, it is only used quite rarely.
For context, with another client device using Intel BE200 Wi-Fi 7 adapter, I hit MCS 12 with SNR about 60-62 dB. In other words, if my noise floor was -95 dBm, my signal would have to be about -35 dBm.
Does iPhone 16 support it then?
According to the above spec sheet, the maximum Extremely High Throughput (EHT) the iPhone can achieve is MCS 11. 4096-QAM only uses MCS indexes 12 and 13. Check the mcsindex.net site.
So, the answer is no, it doesn’t.
Is it a dealbreaker?
From data rate perspective, even without 4096-QAM, and using 160 MHz wide channel, we are talking 2000+Mbps! Obviously depending on how far you are from the access point.
So I personally can’t complain. I value access to the clean 6 GHz spectrum, low latency and low retransmissions rate over maximum throughput.
My WAN link speed of 900 Mbps is my personal bottleneck and I usually don’t transfer huge amounts of data from the phone.
High Tx (transmit) and Rx (receive) rates
On a laptop, I can imagine 4096-QAM to deliver much more value when it comes to performing backups for moving very large software image or video files. Having said that, don’t forget that there is 2.5, 5 or 10 Gigabit Ethernet for that.
iPhone 16 supports tri-band Wi-Fi 7 and Multi-Link Operation (MLO). More specifically, the Enhanced Multilink Single‐Radio (EMLSR) mode. The client connects using 2 different Wi-Fi bands, only actively uses 1 of them and listens on both bands simultaneously. Let’s enable it on an access point and verify that it works.
Multi-Link Operation
We have a 320 MHz channel configured on the 6 GHz radio. This is for experimental purposes only. Please use narrower channel in production to avoid adjacent channel interference with other 6 GHz access points.
The tri-band SSID is announced in 2.4 GHz, 5 GHz and 6 GHz bands. It is up to the client device to choose the preferred band. MLO-capable Wi-Fi 7 clients can also enable the MLO feature.
Although iPhone 16 supports MLO, the phone itself doesn’t indicate if MLO is active or not. So our only option is to monitor it from the access point’s side. This is a consumer access point and it doesn’t provide a huge amount of detail. I am hoping to retest this with a proper enterprise-grade AP when I can.
Single band at a time
From the Association Request sent by the iPhone to the access point, we can see that it advertises support for only one band at a time.
With the default settings of the TP-Link Deco BE85 Wi-Fi 7 access point in place, the iPhone establishes MLO using 2.4 GHz and 6 GHz. It actively uses 6 GHz. 2.4 GHz is there for backup purposes.
TP-Link Deco app shows MLO using 2.4 GHz and 6 GHz
The iPhone uses its 160 MHz wide channel capability and actively pushes all data using the 6 GHz channel 69 as I am trying to demonstrate below using Oscium WiPry Clarity spectrum analyser. Check the “waterfall diagram” that shows the top 160 MHz of the 320 MHz channel being busy processing the data transmission.
MLO in action with iPhone primarily using 6 GHz band
The 2.4 GHz link just sits there in the background, unused. Using the same method, I verified that there is no spectrum utilisation whatsoever on the 2.4 GHz channel.
5 GHz and 2.4 GHz EMLSR MLO mode
When we change Preferred Wi-Fi Band setting to 5 GHz, the iPhone establishes 5 GHz active MLO link and 2.4 GHz as backup.
TP-Link Deco app
6 GHz and 5 GHz EMLSR MLO mode
Now, how do we force MLO using the two modern bands? For the purposes of the demo, I simply disable 2.4 GHz radio on the access point.
Disable 2.4 GHz using TP-Link Deco app
The phone establishes 6 GHz active data connection and uses the 5 GHz band as a backup. How can I be so sure? I watched the spectrum and generated nearly 900 Mbps of data over the wireless link. While the 6 GHz channel shows high utilisation, the 5 GHz channel shows no signs of use.
TP-Link Deco app shows 6 GHz and 5 GHz MLO
On the iPhone, we see active channels 69 in the 6 GHz band. That matches what I’ve just seen using the spectrum analyser.
Active 6 GHz channel 69 using max iPhone 16 channel width 160 MHz
How to trigger MLO band change?
Now, I connect the iPhone using 5 GHz channel. I am going to saturate the channel with other client’s traffic. My hope is that high channel utilisation makes the iPhone stop using the 5 GHz channel and switch to the backup 2.4 GHz channel.
And the result? It correctly detected and reported high channel utilisation, but the MLO band change did not happen.
High channel utilisation
So channel utilisation on its own did not do the trick for me. Perhaps the algorithm penalises and tries to avoid the 2.4 GHz band which is typically in a much worse condition than 5 GHz? Or high channel utilisation must persist for a longer period of time? Time will tell.
What chipset does it use? To find out we are going to enable Personal Hotspot on the iPhone and see what information we can get from the information elements it broadcasts in its beacons.
As we can see here, iPhone 16 uses Broadcom Wi-Fi 7 chip. That’s about the level of detail we can capture from the beacon frames it sends.
Broadcom chip
Continue reading
Does the iPhone 16 support Multi-Link Operation? Check this blog post.
All iPhone 16 models support tri-band Wi-Fi 7 as you might have seen here. But what is the maximum channel width they support in the 6 GHz band?
iPhone 16
Although my Wi-Fi 7 access point uses 320 MHz wide channel, the maximum 6 GHz channel width iPhone 16 supports is 160 MHz.
AP using 320 MHz wide channel
Here is the client view of the world.
iOS Wi-Fi Diagnostics profile provides extra information
Spectrum view
I am using Oscium WiPry Clarity 6 GHz spectrum analyser to see the spectrum. When we run a WAN speed tool Speedtest.net (it is not designed to be a Wi-Fi test tool) to generate some traffic here and see how it utilizes the 160 MHz channel.
Outside of that, I also checked the 2.4 GHz channel. There was no activity there. So that proves that only one of the 2 bands involved in MLO is active at a time.
Only the 6 GHz channel is active during data transfer, 2.4 GHz isn’t actively used
Updated: Apple’s iPhone 16 Wi-Fi specification
New documentation is now available directly from Apple. Note that 160 MHz is the maximum channel width for all models.
iPhone 16 Wi-Fi specification published by Apple
You normally won’t use 320 MHz wide channel anyway in Europe
Having said that, at least in Europe, we only have one 320 MHz wide channel available. So by the time you add a second access point you will have to downgrade to 160 MHz channels or narrower. That is to prevent the 2 APs from stepping on each other’s toes and causing adjacent channel interference. No support for 320 MHz channel width on the iPhone is not really a problem.
If you were considering using 320 MHz channels, or if your vendor uses that as a factory default setting, please be a good citizen and don’t.
All iPhone 16 models now support Wi-Fi 7 and come with 2×2 MIMO 2-Spatial Stream radio configuration. But Wi-Fi 7 doesn’t make support of 6 GHz band mandatory. So technically there could be Wi-Fi 7 clients that only support 2.4 GHz and 5 GHz.
Do iPhones 16 support all three 2.4 GHz, 5 GHz and 6 GHz Wi-Fi bands?
I tested a standard non-Pro iPhone 16 model.
It indeed supports all three Wi-Fi bands. Here is a proof of iPhone 16 connected to a Wi-Fi 7 access point using 6 GHz channel 69.
iPhone 16 connected using the 6 GHz Wi-Fi band
Using the My Wi-Fi Apple Shortcut we can look into another level of detail. In this case the iPhone is using the 802.11be Wi-Fi 7 standard to communicate with the access point.
iPhone 16 using Wi-Fi 7 802.11be standard
Association Request
As the iPhone associates to the AP, it announces no support for 320 MHz channel width.
The Realtek RTL8126 chip we are testing today is so far the most suitable for Raspberry Pi 5. It is capable of 5 Gigabit Ethernet at full speed. TCP iperf3 throughput peaks at 4.7 Gbps. It doesn’t overheat. And it doesn’t excessively utilise the Raspberry Pi 5 CPU.
This particular one is sold under the iocrest brand. Like the other boards and adapters there is no increst branding on it and it will likely be sold under various brands. The RTL8126 chip is the key component here.
Raspberry Pi 5 with 5 Gigabit Ethernet network adapter
How did we connect it to the Pi? Via PCIe bus. We breakout the Raspberry Pi 5’s PCIe connector via Pineboards (aka Pineberry Pi) board to M.2 M-key slot. And in that slot we install the iocrest 5 Gigabit Ethernet network adapter – that’s the black M.2 module, plus a PCB with RJ-45 connector on a grey ribbon cable.
iocrest 5 GbE adapter connected to Raspberry Pi 5 via PCIe Gen 3 linkCloser look at the adapter
Here is how it looks from PCI device perspective.
Performance
It has no problem negotiating full duplex 5 Gigabit Ethernet and filling the interface with traffic fully.
5 GbE Full duplex
iperf3 with default TCP settings peaks at 4.7 Gbps up and down. More parallel streams don’t improve the result any further. This is in PCIe Gen 3 mode.
Full 5 Gigabit Ethernet throughput in PCIe Gen 3 mode
Just for the record, if we downgrade PCIe bus to Gen 2 link speeds, we are talking 3.43 Gbps down and 3.31 Gbps up iperf3 TCP throughput-wise.
Throughput in downgraded PCIe bus to Gen 2 mode
Thermal footprint
Fully loaded by TCP traffic, I see temperature of 81.2° C (178° F) on the top surface of the RTL8126 chip. Yes, it is on the warmer side, but Raspberry Pi 5 SoC runs quite warm too and it is nowhere near 122° C temperatures I observed on this “hot” 10 Gigabit Ethernet adapter.
Chip temperature, installed in Intel NUC with M.2 slot
By the looks of it, there is no temperature sensor on the PHY so I can’t measure internal temperature.
CPU utilization and temperature of fully loaded adapter with TCP traffic
Linux software support
I happened to have Raspberry Pi OS with 6.8.0-rc7 kernel running on the Raspberry Pi 5. Out of the box, the adapter did not work. iocrest included driver download link pointing to this Chinese website but I am not so sure I want to use that one.
This adapter in PCIe Gen 3 mode draws about 1.5 W in idle, and 2.1 W under full iperf3 load.
Switching the adapter to Gen 2 mode doesn’t make any power savings. I measured 0.1 W less in Gen 2 mode.
The whole setup of Raspberry Pi 5 with fan, Pineboards PCIe adapter, and this 5 GbE adapter in PCIe Gen 3 mode draws about 5.1 Watts in total under full iperf3 load.
Does it work on Windows 11?
Yes, it does. I installed one in Intel NUC 12th generation. It runs at full speed full and Gen 3 x1 mode.
Windows 11 driver (as of May 2024) downloaded automatically via Windows Update only allows this adapter to use 2.5 GbE. To unlock 5 GbE we download driver directly from Realtek’s website and we are all set.
Driver from Realtek’s website with full 5 GbE support5 GbE full duplex with driver from Realtek’s websiteIntel NUC with 5 GbE RTL8126 adapter
With the adapter inserted in M.2 M-key slot, we won’t be able pop the NUC bottom lid back on. The adapter is just a bit too tall.
Bottom lid won’t fit with the adapter installed
Throughput also looks good. I might revisit Windows throughput testing tools at some point. But for now, I take 4.74 Gbps down and 4.42 Gbps up speeds. Increasing number of parallel streams did not improve throughput in any way.
Windows 11 throughput test
For the record, Jumbo frames seem to be supported but I had no reason to explore this further this time.
Jumbo frame support on Windows 11
Summary
As I mentioned towards the beginning, 5 Gigabit Ethernet based on Realtek RTL8126 chip seems to strike the perfect balance for Raspberry Pi 5. It delivers 4.7 Gbps up and down, doesn’t consume much power, and doesn’t produce excessive amount of heat.
Long-time test will tell how it actually performs but for now I am happy with what I’ve seen.
From driver perspective, I am wondering if the latest Linux kernel supports this chip natively or if I can enable the right kernel module manually.
