There are three basic modes that a Wi-Fi device can use. These wireless network modes determine the device's role in it. The configuration method depends on the types of connections that you want to use between its nodes. In addition to user phones, tablets and laptops, routers are used to manage the network. They can connect one network to another, determine what traffic passes between them, and perform other functions on the network, such as assigning an IP address.
After the initial launch of the 802.11b Wi-Fi standard, it has become the most widespread among consumer devices due to its low cost. Three years later, it was replaced with the faster 802.11g, which retained backwards compatibility to support existing hardware, while still having some of the drawbacks of older models. The next major wireless mode standard in the world, 802.11ac, was released in 2013 and became the mostsought after by many mobile device owners.
A Brief History of Standards
If a user has set himself the goal of creating a fast network in his home or office, you need to understand the technical parameters of the network and equipment, and first of all, you need to understand what this strange 802 number means.
Actually, the naming system uses a number of network standards. Ethernet networks start with 802.3, Bluetooth is prefixed with 802.15, and Wi-Fi is designated 802.11. All different Wi-Fi options will start with this 802.11 number followed by a letter or two that identify network properties such as the maximum speed and range of the specific device.
To ensure the compatibility of the wireless network mode with various equipment, there is a list of Wi-Fi 802.11: a, b, g, n and ac in the specification for many smartphones. It covers all the old and most common modern standards to help identify incremental improvements in the model, mainly in terms of speed gains.
In 1970, the University of Hawaii developed the first wireless data transmission network between the islands of the same name. However, it wasn't until 1991 that the Institute of Electrical and Electronics Engineers (IEEE) began discussing the standardization of WLAN technologies. In 1997, the IEEE ratified the initial 802.11 standard with the term "802.11 technology" to which Wi-Fi refers.
In 1999, communication was introduced to the general public with the ratification of 802.11 a and b wireless networking modes. These standards had very low speeds, down to 54Mbps and 11Mbps respectively, but that was normal for the time because there were no portable mobile phones using Wi-Fi and very few laptops.
However, by 2003, mobile devices using Wi-Fi appeared, and portable laptops became more common in both business and personal use. It was then that the 802.11g standard was approved, providing speeds up to 54 Mbps in the 2.4 GHz space. In 2007, the first smartphone was released, and with it came 802.11n ratification.
The n standard provides faster processing speeds (up to 450Mbps) for Wi-Fi and support for 2.4GHz and 5GHz devices. Today, smart devices are reliable enough to replace dedicated, more expensive laptop technology, so wireless has begun to catch up.
In 2013, the gigabit Wi-Fi standard 802.11ac appeared. 802.11ac is a fantastic new wireless technology that has taken humanity into the era of gigabit Wi-Fi.
Three wireless network roles
The role of the network defines the goals and the equipment that can fulfill them.
Wireless clients (Station). Devices such as computers, tablets and phones are common clients on the network. When a user accesses a wireless access point or router in a home or office, their device is a client. This is the wireless operating mode.client network is also known as "station mode". Some routers can work in this capacity, which allows them to function like a wireless card in a PC and connect to various access points. Station can connect two Ethernet networks or connect to more remote access points. Wireless client - accesses information through the same channel.
Access points (Master). Most wireless networks use access points, devices that host and control a wireless connection for laptops, tablets, or smartphones. If Wi-Fi is used at home and in the office, then this happens through an access point. When the router is configured as an access point, it is in Master or Infrastructure mode. Access points can cover a range of areas with a wireless signal, it all depends on the power of the device and the type of antenna. The user needs to know this before deciding which wireless network mode to choose
Special knot (Mesh). Some wireless devices such as laptops, smartphones, or wireless routers support Ad-Hoc mode. This allows these devices to communicate with each other without an intermediate access point controlling the network. This standard forms a different type of network. In Ad-Hoc mode, all devices are responsible for sending and receiving messages to other devices - there is nothing else between them. On a network, each device must play these roles and use the same configuration to participate. Not all devices use this mode, and some use it as "hidden"function.
Special devices are used to create a mesh network, so when they are in this mode they are called "mesh nodes".
Packet devices in networks
In order to provide the functionality of the wireless networks described above (Clients, Access Points, and Ad-Hoc Hosts), you need devices configured for different roles:
- Home or office network. This kind of wireless network is usually a combination of a router and a wireless access point (AP). In many networks, they can be combined into one device. They are usually simply called routers and have a DSL port, cable, 3G or 4G to connect to the internet. In large office scenarios, there may be multiple APs distributed throughout the building to provide uniform wireless coverage.
- Point-to-point - long distance connections. Such networks can be used to connect remote buildings or areas. This usually requires very focused antennas, such as dishes (an antenna that can send a narrow beam in a specific direction). Long distance service is often referred to as point-to-point or PtP. The title describes the concept: two dots are connected and nothing else. The standard requires two wireless devices: one must be configured as an access point, the other as a client.
- Long distance access point and client connection. This is another example of point-to-point communication where routers have antennas for longer range.connections. Two wireless devices are connected to each other, the antennas determine the range in which they can connect. The more focused the signal, the farther the point-to-point communication can go. As the distance between devices increases, it becomes more important to focus the signal with antennas (at both ends of the connection).
- Point to MultiPoint is a wireless ISP model. If you combine the two principles used in the above networks, multi-client devices connected to an access point, and more powerful antennas used for external devices to create longer channels, then you can create multi-point networks. These are large networks of access points, where in the “center” there is one device that controls all clients connected to it and connects them to the Internet. These types of networks are used by wireless Internet service providers (WISPs) to connect homes and businesses to the network. Instead of laying cables around a district or city, ISPs install one or more powerful access points on the tallest building or tower.
- Mesh - A mesh network uses the point-to-multipoint principle and is based on the idea that every node connects to every other node in the range. Essentially, this creates a Multipoint-to-Multipoint network. This requires all devices to be in Ad-Hoc mode. Devices in AP mode or client mode cannot perform the same function. Wireless mesh nodes are installed on the roofs of various buildings and those nodes that are in the coverage area and do not have blockingsignals will connect. They will share all their associated resources and connect to computers, access points, or building routers to provide users with resources anywhere on the network.
- Hybrid networks. When designing and building urban or public networks, it can be difficult or impossible to use one method to connect subscribers in bulk. For example, one point-to-multipoint network may not cover an entire area. Grid nodes can be used to expand client sites in adjoining buildings. Point-to-point connections can connect long distances and connect multiple disparate networks. In this option, there is no single example that would cover all possible uses of the network.
Wired Equivalency (WEP) privacy
This model was developed in the late 1990s as the first 802.11 encryption algorithm with one main goal - to prevent hackers from attacking wireless networks with access points (APs). However, from the very beginning, WEP lacked the strength to cope with the task.
Cybersecurity experts discovered several serious flaws in WEP in 2001 in legacy wireless mode, which eventually led to industry-wide recommendations to phase out WEP on both corporate and consumer devices.
After a large-scale cyberattack against TJ Maxx in 2009 wastraced back to vulnerabilities identified by WEP, the Payment Card Industry Security Standard prohibited retailers and other organizations that processed credit card data from using WEP.
WEP uses the RC4 stream cipher for authentication and encryption. The standard first defined a 40-bit pre-shared encryption key. The 104-bit key was made later. The key was entered manually and updated by the administrator.
The legacy wireless network mode key is combined with a 24-bit initialization vector (IV) to strengthen encryption. However, a small IV size increases the likelihood of key reuse, which in turn makes them easier to crack. This characteristic, along with a number of other vulnerabilities, including problematic authentication mechanisms, makes WEP a risky choice for wireless network security.
Wi-Fi Protected Access (WPA)
In 2003, the Wi-Fi Alliance released WPA as an interim standard, and the Institute of Electrical and Electronics Engineers (IEEE) worked on a more advanced and long-term replacement for WEP.
WPA has separate modes for corporate users and personal use. Enterprise Mode (WPA-EAP) uses stronger 802.1x authentication with EAP. WPA-PSK Personal Mode uses pre-shared keys to simplify deployment and management of users and small offices. Enterprise mode requires the installation of an authentication server.
Although WPA is also based on the RC4 cipher, it introducedseveral encryption enhancements, namely the use of the Temporal Key Integration Protocol (TKIP). The protocol contains a set of features to improve network security:
- Using 256-bit keys, mixing keys for each packet.
- Generate a unique key for each package.
- Automatic distribution of updated keys, message integrity check, large IV size (48 bits).
- Mechanisms to reduce reuse IV.
WPA was designed to be backwards compatible with WEP to enable fast and easy implementation. Network security professionals have been able to support the new standard on many WEP-based devices with a simple firmware update. This structure failed to provide adequate security, yet it was not as secure as users wanted.
WPA2: Modernization of an outdated standard
WPA2 was approved by the IEEE in 2004 as 802.11i. Like its predecessor, WPA2 also offers corporate and personal modes and still has vulnerabilities. However, today it is considered the most secure wireless security standard.
WPA2 replaces RC4 and TKIP with two stronger encryption and authentication mechanisms - Advanced Encryption Standard (AES) and Counter Mode with Authentication Code and Cipher Message Chain Protocol (CCMP).
Designed for interoperability, WPA2 supports TKIP inas a fallback if the device cannot support CCMP. AES consists of three symmetric block ciphers. Each encrypts and decrypts data in 128-bit blocks using 128, 192 256-bit keys. While the use of AES requires more computing power from access points and clients, continuous improvements in computer and networking hardware have reduced performance issues.
CCMP protects the confidentiality of data by allowing only authorized network users to receive it, using a message authentication code in the cipher block chain to ensure message integrity. WPA2 also introduced smoother roaming, allowing clients to move from one access point to another on the same network without re-authenticating, using master key pair caching or pre-authentication.
802.11 infrastructure mode
The 802.11 standard defines two modes of operation:
- Infrastructure mode in which wireless clients connect to an access point. This is usually the default mode for 802.11b cards.
- Ad hoc mode where clients connect to friends without any access point.
In infrastructure mode, Asus with wireless network mode, known as STA, connects to an access point via a wireless connection. The node formed by the access point and stations located within the coverage area is called the basic service set, in English it is denoted by BSS and is a chip. EachThe BSS is identified by the BSSID, a 6-byte (48-bit) identifier. In infrastructure mode, the BSSID corresponds to the MAC address of the access point.
It is possible to connect several access points together, or more precisely, several BSSs, through a link called a distribution system, denoted by DS to form an extended service set or ESS. The DS distribution system can be a host network, a cable between two access points, or a wireless network.
ESS is identified by an ESSID (Service Set Identifier), that is, a 32 ASCII character identifier as a name for the network. The ESSID is often connected to the SSID, shows the network name in the first security layer. When a mobile user switches from one BSS to another, when moving to the ESS, the wireless network adapter of his device may change access point depending on the reception quality of signals from different access points.
They communicate with each other through the distribution system to exchange information and, if necessary, transmit data from mobile stations. This feature, which allows stations to easily switch from one access point to another, is called roaming. Most routers have several connection options, including legacy or n only wireless network mode, for example for ASUS RT-N18U.
Connecting with hotspot
When a station enters a cell, it sends a verification request to each channel containing the ESSID for which it is configured, as well as transmitting data supported by the Asus adapter with wireless network mode. If aESSID is not configured, the station is listening on the network for SSID.
Each access point regularly sends a frame (at a rate of about one every 0.1 seconds) with information about the BSSID and characteristics. The ESSID is automatically broadcast by default, but it is possible (and recommended) to disable this option.
For each request received, the access point checks the ESSID and rate request present in the beacon frame. If the ESSID matches the ESSID of the access point, then sends a response containing information about its loading and data synchronization. In this way, the station receives a response and can see the quality of the signal. It emits an access point to determine the distance at which it is. In fact, the closer the access point in wireless network mode, the better the Internet quality.
A set of independent basic services
In ad hoc wireless client mode, machines connect to each other to create a peer-to-peer network, that is, a network in which each machine acts as both a client and an access point. The set formed by the various stations is called the Independent Basic Services Set - IBSS.
Thus, IBSS is a wireless network of at least two stations that does not use an access point. IBSS is an ephemeral network that allows people in the same room to share data. IBSS is identified by SSID, just like ESS infrastructure modes in wireless networks.
In an ad hoc network, the scope of an independent BSS is determined bythe scope of each station. This means that if two of the network stations are out of range of each other, they will not be able to communicate even if they "see" the other stations. Indeed, unlike infrastructure mode, ad hoc mode does not offer a distribution system capable of transferring frames from one station to another. Thus, IBSS is by definition limited to the wireless network.
Mixed transmission mode
The 802.11n or wireless n standard offers a number of advantages over older Wi-Fi 802.11 a, b and g standards. Although the 802.11 a and b standards have now largely disappeared, there are still a number of marketplaces where you can purchase 802.11 g wireless routers, and many people still use equipment that uses this old standard, such as Asus' legacy wireless networking mode.
If the user uses the entire wireless network n, and everything connected to the network is wireless n, then he will have no problems and everything will work at full wireless speed n. If he is using wireless network n with some old wireless devices b or g connected to it, then the network must slow down for these old devices to keep up. This means that such a scheme loses some advantages in wireless network speed n even on other wireless devices n.
Most routers allow you to switch modes, the user must select the modewireless network n or legacy.
The most common schemes are described below:
- Legacy mode - allows a/b/g standards to communicate with wireless router n, everything works at low speed.
- Mixed Mode - Allows a/b/g devices to communicate with wireless router n at wireless G speeds, but with some of N's benefits.
- Full n mode - allows only wireless n devices to communicate with the router and gives you all the benefits of N wireless network.
New routers automatically switch between modes so you can be sure the best available speed and range will always be delivered. For some device brands, security settings may cause the router to operate at slower speeds, such as WPA1 on Netgear routers.
Thus, we can sum up which wireless network mode is better to choose. If the user has the option to choose between g and n modes, n should always be chosen. Almost every router will work with the old standards, but users will not get all the benefits of the new standard, and only when they finally get rid of the old wireless g-devices will they feel the full benefits of the wireless network n.