Wwan Hca Slot
A Wireless Wide Area Network or WWAN is a way to connect to the Internet without wires, achieved using cellular tower technology. Cellular service companies offer this type of connection for a monthly fee, or alternately on a pay-as-you-need-it basis. The connectivity allows a user with a laptop and a special card to surf the Internet, check email, or connect to a Virtual Private Network (VPN) from anywhere within the regional boundaries of cellular service.
Jul 07, 2019 Short of hacking the BIOS, or building a new type of USB 3.0 card from scratch, only WWAN cards will work in the WWAN slot. Yours may differ. Older Dell models did have SATA+PCIe in the WWAN socket, but this is not the case for more recent units. The story will inevitably be different for other manufacturers. Two M.2 Expansion slots: 1 WWAN/HCA and 1 WLAN/BT/WiGig EDock port Lock slot Dimensions & Weight1,16 Width: 13.2” / 334.9mm Height (front): 0.9“ / 23.2mm Depth: 9.1” / 231.1mm Starting weight: 3.88 lbs. / 1.76 kg Based on 4 cell battery, M.2 SSDA, non touch FHD LCD Regulatory and Environmental Compliance1 Regulatory Model: P62G Regulatory.
As people become more dependent on online technology to conduct business and keep information flowing, wireless connectivity has become a virtual necessity. Many hotels and communities offer local connectivity, but coverage is often spotty or nonexistent. WWAN can all but guarantee connectivity when the user needs it.
To take advantage of this technology, a user must first purchase a WWAN PC card for his or her laptop unless the connectivity is built-in. By purchasing the card and paying a monthly fee, the user only needs to slip the card into the PC-card slot (sometimes known as the PCMCIA slot) to access the service. Plans vary among providers but most are rated according to data download caps.
In some cases, a person may not require 24/7 access to the service, but would like to use it occasionally when free local networks are not available. Some providers have plans that allow users to pay by the day for connectivity. By using the WWAN card, the person commits to a small charge, securing a 24-hour pass. At the end of the 24-hour period, the user can no longer connect, unless he or she purchases another pass.
As an alternate to a WWAN card, it is possible to connect some cell phones directly to a laptop using a Universal Serial Bus (USB) cable. The cell phone acts as a modem to patch the laptop into the Internet. This is only possible with certain phone models and plans, and the data transfer speed will be slower than connecting with a WWAN card. Before using this method, users should check with their cell phone provider to see what charges might apply, if any.
While there are certainly less expensive ways to get wireless connectivity in many cases, few cover the territory offered by WWAN for those visiting, living, or working in remote or “nonwired” areas. The service is commonly available in regions where services like Digital Subscriber Line (DSL) and cable might not be. It can also be an international solution for global travelers, offering one more option for staying connected.
Recently while trying to answer this myself, I found a lot of discussion on this subject, but no definitive answer.
M.2 B Key sockets have a variety of possible modes as defined by the NGFF specification:
Wwan Hca Slots
The second to last mode “RFU” (Reserved for future use) is defined by Dell as:
Wwan Hca Slot Login
I am unsure what HCA stands for, but have seen it printed on the silkscreen of some of my earlier latitude models. Clearly it is some kind of proprietary device that requires one PCIe lane. It may stand for Host Channel Adapter – Implying some kind of non-NVMe PCIe SSD (i.e. has an Option ROM).
None of this tell us anything about what Dell have actually implemented on thier WWAN slots, neither does their tech support, or any of their documentation. I found myself eyeballing the traces extending from the socket, but even this was inconclusive as a lot of them are fed up from vias under the socket.
It’s given that it’ll have SSIC/USB 2.0 because almost all WWAN cards use those interfaces, but what of the others?
Fortunately there’s no need for any further conjecture because the schematics for these models are floating around the internet, so let’s answer that question definitely.
The above diagram covers models 7280, 7380, 7480, 7490 and likely others too. So there we have it. The interfaces on the WWAN socket are:
- USB 2.0
- SSIC (Chip-to-Chip USB 3.0)
- PCIe (Permanently disabled in BIOS)
No SATA.
But…
Just because we know what interfaces are there, we still don’t know what kind of peripherals will actually work. For example – if a socket can accept WWAN-PCIe – SSD-PCIe should also be no problem as the required connections are all there, however those devices will have their configuration pins tied differently, allowing the BIOS to determine exactly what’s attached.
This allows manufacturers (for example) to allow PCIe WWAN cards, but disallow PCIe SSDs. On top of that, just because an interface is there, it doesn’t mean that it’s actually enabled.
This turns out this is the case for my Dell Latitude. While the PCIe is there, it cannot be used because the port on the root complex is disabled in the BIOS, and there’s no way to enable it (without hacking the BIOS). I was able to confirm this by testing out a variety of B-Key PCIe devices, none of which were detected (even when strapped as WWAN-PCIe).
A dick move by dell, but given how rare WWAN cards requiring PCIe are, they had no reason to enable it, and my experience from owning previous models is that they’re pretty good at tying up loose ends like this.
Short of hacking the BIOS, or building a new type of USB 3.0 card from scratch, only WWAN cards will work in the WWAN slot.
Older Dell models did have SATA+PCIe in the WWAN socket, but this is not the case for more recent units. The story will inevitably be different for other manufacturers.