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Wireless Networking

4G wireless technologies and connected devices only contain a glimpse of the impact that 5G will have: the next generation of wireless connectivity. Many organizations do not realize the magnitude of this transformation in their day-to-day business and the impact that 5G will have in the evolution of Industry 4.0.

Manufacturers, supply chain companies, and other enterprises require mobile networks nowadays to deal with flexible enterprise-grade industrial connectivity for the most advanced machines. Wireless networks were the domain of ‘road warriors’ in the past, but wireless is currently displacing Power over Ethernet networks. Wi-Fi networks are the primary connectivity of choice across a broad range of industrial use cases due to the ability to deliver an unrivaled balance of capacity, bandwidth, flexibility, and security (with the introduction of WPA4). 4G Wi-Fi is well established in enterprise IT network environments. For the operational technology (OT) network that delivers connectivity for the 24×7 production line, you should look to 5G to support digitization across a wide range of manufacturing and supply chain cases.

Soon you will see a wide range of solutions for Industry 4.0 mobile network deployments for 5G based that you base on a diversification of the equipment supply industry enabled by ‘open networking’ and open-source initiatives.

Wireless networks work differently compared to Power over Ethernet, and because wireless takes over the “old-school” networks, it is essential to understand how they work. How wireless operates still eludes many people, maybe because wireless networks are relatively inexpensive and easy to configure. Because of this, it doesn’t challenge users and technicians to the “hows” of wireless. In this post, I will show you the basics of wireless networks.

Components of a Wireless Network

You interact within wireless networks with radio waves or beams of infrared light. Wireless radio wave networks are nowadays supported based on the IEEE 802.11 Ethernet standard (which is marked as Wi-Fi) and Bluetooth technology. Wireless networks that use infrared light are limited, and the networks that use this form use the Infrared Data Association (IrDA) protocol. Although infrared networks still exist, I expect them to become obsolete over time. Wi-Fi and Bluetooth have become the industry standard.

Suppose you want to extend the capabilities of a wireless Ethernet network, such as connecting to a wired network or sharing a high-speed connection. In that case, you need a wireless access point (WAP). A WAP centrally connects wireless network nodes in the same way that a hub connects wired Ethernet PCs. A lot of WAPs nowadays also act as switches and Internet routers. You can see a network node as a connection point you use in a communications network, and each node is an endpoint for data transmissions or redistribution. Examples are routers and devices with a network connection, such as computers, tablets, and mobile phones.

Most WAPs draw power from a wall outlet. Still, the last generations of WAPs also use Power over Ethernet: you only need to plug a single Ethernet cable into the WAP to provide it with both power and a connection to your network. The power and network connection are both supplied by a PoE-capable switch. Some people call WAPs just APs: Access Points, but it’s the same.

Wireless Network Software

A wireless device uses the same networking protocols and clients as its wired counterparts. The wireless device uses the carrier sense multiple access/collision avoidance (CSMA/CA) networking scheme. The Collision avoidance aspect slightly differs from the collision detection standard wired Ethernet uses. A wireless node listens on the wireless device to see if another node is broadcasting any data.

Wireless nodes have a more challenging time detecting data collisions, but to cover this, they offer the option of using the RTS/CTS (Request to Send/Clear to Send) protocol. When this protocol is enabled, a transmitting node sends an RTS frame to the receiving node after the protocol has determined that the wireless device is clear for usage. The receiving node then responds with a CTS frame, and this frame tells the sending node that it is okay to transmit. Once the node transmits the data, the transmitting node waits for an acknowledgment (ACK) from the receiving node before it sends the next data packet. RTS/CTS introduces significant overhead to the whole process, though: it can negatively impact performance (read: less speedy connection).

Additional hardware must not be installed when you want to use a wireless network. Wireless network adapters are plug-and-play: Windows and macOS immediately recognize one when installed and will only ask you to load any needed hardware drivers if your OS doesn’t automatically install this.

You only need to set the parameters, such as the network name. Windows and macOS have built-in tools for configuring these settings. Still, some wireless adapters also come with configuration tools that the wireless network adapter provider provides.

Wireless Configuration Utility in Windows 11

Wireless Network Modes

The simplest form of a wireless network consists of two or more computers/devices that communicate directly without cabling or any other intermediary hardware. More complicated wireless networks use a WAP/AP to centralize wireless communication. You also use complex wireless networks to bridge wireless network segments into wired network segments. You call these two methods ad hoc mode and infrastructure mode.

The “Ad Hoc Mode

The “Ad Hoc” mode is sometimes also called peer-to-peer mode. Every wireless node is in direct contact with every other node in a decentralized “free-for-all” setup. When two or more wireless nodes communicate in ad hoc mode, you call this an IBBS (Independent Basic Service Set). Ad Hoc mode is most suitable for networks that consist of small groups of devices (< 10) that require a transfer of files, must share printers, and/or require a temporary network (for instance, business meetings or a study group).

Ad Hoc Network

Infrastructure Mode

Wireless networks run in infrastructure mode using one or more WAPs/APs to connect the wireless network nodes to a wired network segment. A single WAP, called a BSS (Basic Service Set), services a given area, and you can extend a specific service area by adding more WAPs. When you do this, you call it EBSS (Extended Basic Service Set).

Infrastructure Mode

A wireless network that runs in infrastructure mode requires more planning than an Ad Hoc Network and is more complicated to configure. The significant advantage is that this gives an administrator much control over how the network operates.

The Service Set Identifier

The Service Set Identifier (SSID) is the network’s name, and the SSID defines the wireless network. Wireless devices want to be heard, so you usually configure WAPs to announce their presence by broadcasting the SSID to their maximum range.

In addition, the SSID also gives important clues about the manufacturer (and sometimes even the model) of an access point.

You should always change the default SSID name into something unique and change the password right away: basic security hygiene. Although new SSID models come with unique SSIDs and passwords, the SSID can still leak information about hardware, and the generated password can have a set of rules easily cracked by someone who wants to hack the network.

Remember to configure every wireless access point with the same unique SSID name. Otherwise, the AP rejects data packets that lack the correct SSID name in the header.

Example of a Service Set Identifier

Securing a Wireless Network

When you set up a wireless network, you need to remember that you can limit the risk by hiding the network from outsiders. When you use an omnidirectional antenna that sends and receives signals in all directions, you should keep it near the center of your home or office. The closer the antenna is to a wall, the further away someone from the outside can still detect your wireless network.

You can adjust the radio power levels of the antenna of many wireless access points. You can decrease the radio power until you can get reception at the furthest point inside the target network space but not outside. It requires some “trial and error” to do this, but it’s worth the time. It would help if you never forgot to secure the WAP. You have to ensure it because most WAPs have physical Ethernet ports in addition to their wireless capabilities. These ports are not password-protected or encrypted, so keep the WAP in a location that is not easily accessible by outsiders: placing it on ceilings high above the ground.

In addition, modern wireless networks use three methods to secure access to their network and their transferred data: MAC address filtering, authentication, and data encryption. 

MAC address filtering

Most WAPs support MAC address filtering. This method enables you to limit access to your wireless network based on the physical, hard-wired address of the units’ wireless Network Interface Controller (NIC). A table in the WAP lists stores the MAC addresses permitted to participate in the wireless network. The WAP rejects any data packets that don’t contain any of the listed MAC addresses.

Authentication

As with wired authentication, wireless authentication enables the system to check a user’s credentials and provide or deny the user access to the network. Always use an authentication process and rotate the wireless password(s) after a certain period (for instance, every quarter).

Encryption

Encryption scrambles the signals on radio waves and makes communication between users secure. Several generations of wireless security protocols exist WEP, WPA, WPA2, and WPA3. WPA3 is the safest option which you should always use if your Access Point supports this. WEP and WPA are options you should never choose. These are very outdated security protocols and are easy to crack. One of my previous posts describes the different security protocols in detail.

Final Thoughts

In the past, you could easily access wireless networks, walk into a WAPs coverage area and turn on a wireless device, and connect. These days are over, but occasionally you can still run into legacy systems with outdated WAPs that are directly accessible. Always be aware of that and when this is the case, make sure to inform the organization about this.

Although wireless networks are slowly taking over wired infrastructure in organizations, many organizations still use a hybrid solution in which you combine wireless with Power over Ethernet. With this, Power over Ethernet can also be used as a failsafe when something happens with the wireless connection or when the wireless connection is underperforming. I always recommend keeping the old infrastructure running because of this failsafe and not disposing of a physical network. 

Finally, I would make the point that wireless is not entirely wireless, and it would be best if you still connected through cables. Without cables, there is no wireless connection. I think most people don’t realize that cables still manage our complete infrastructure: it’s essential to know this. It means that we still depend heavily on the quality of the cable infrastructure. Feel free to contact me if you have any questions or if you have any additional advice/tips about this subject. If you want to keep me in the loop if I upload a new post, do not forget to subscribe to receive a notification by email.

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