What Is an Access Point?

How Does an Access Point Work?

The following figure shows a unidirectional data flow from STA A to STA B across a wired network.

1. STA A sends data to the transmitting AP over the air.
2. The transmitting AP encapsulates the wireless data into wired data and then sends the wired data to the receiving AP over the wired network.
3. The receiving AP converts the wired data into wireless data and then sends the wireless data to STA B.

In the wireless data forwarding process shown in the preceding figure, APs bridge wired and wireless networks together. How is wireless data transmitted between an AP and a STA?

As shown in the following figure, the transmitter applies source coding to convert information, which may be an image, text, sound, or other types of information, into digital signals that allow for circuit calculation and processing. It then converts the digital signals into radio waves by means of channel coding and modulation. The radio waves are then transmitted over air interfaces and wireless channels. After receiving the radio waves emitted by the transmitter, the receiver converts them into information through demodulation and decoding.

• Source coding: a process of converting raw information into digital signals by using a coding scheme. Source coding can reduce redundant information in the raw information, by compressing the information to the maximum extent without distortion. Different types of information require different coding schemes. For example, H.264 is intended for videos.
• Channel coding: a technology for detecting and correcting information errors to improve channel transmission reliability. With wireless transmission that is prone to noise interference, information arriving at the receive end may be erroneous. Channel coding is introduced to restore information to the maximum extent at the receive end, thereby reducing the bit error rate. WLAN uses two channel coding schemes: Binary Convolutional Encoding (BCC) and Low Density Parity Check (LDPC).
• Modulation: a process of signal superimposition. Digital signals in circuits are instantaneous changes between high and low levels. During the transmission, antennas can convert the digital signals into radio waves and then send them out. This can be completed only after the digital signals are superimposed on high-frequency signals generated by high-frequency oscillation circuits. Having no information itself, a high-frequency signal is only used to carry information and is therefore called a carrier. The modulation process encompasses symbol mapping and carrier modulation, which commonly use quadrature amplitude modulation (QAM) and orthogonal frequency division multiplexing (OFDM) technologies, respectively.

• Air interface: an invisible interface used in wireless communication. Unlike physical interfaces and cables on wired devices, air interfaces cannot be perceived and are connected to each other over the air.
• Channel: a media for transmitting signals. The wireless network standard 802.11 defines the allowed wireless channel frequency bands and specific frequency ranges.

How Does an Access Point Relate to WLAN and Wi-Fi?

Wi-Fi is a trademark of the WFA, and is also a wireless network communication technology based on IEEE 802.11. The WFA has announced the use of Wi-Fi to improve the interoperability of products in compliance with IEEE 802.11 standards.

WLAN is short for wireless local area network. Quite simply, WLANs provide network communication using radio waves such as lasers and infrared signals, instead of physical connections. They provide wireless network communication using high-frequency radio waves (such as those on the 2.4 GHz, 5 GHz, and 6 GHz frequency bands) and comply with IEEE 802.11 standards. WLAN in our daily life refers to that implemented based on IEEE 802.11 standards. During the evolution and development of WLAN, various technical standards have emerged, such as Bluetooth, Wi-Fi, and HyperLAN2. Among them, Wi-Fi is now most commonly used due to its advantages such as simple implementation, reliable communication, high flexibility, and low implementation costs. Gradually, Wi-Fi becomes a synonym of WLAN.

Simply put, Wi-Fi is the mainstream communication technology used by APs to provide wireless access services, and a WLAN is a wireless local area network formed by devices such as APs and ACs.

What Are the Types of Access Points?

Depending on their market positioning, APs can be classified as home or enterprise APs.

• Home AP: predominantly used in home scenarios, allowing family members to access the Internet. In typical scenarios, a small number of home APs are deployed on a WLAN, providing wireless access to several or a dozen STAs. Such a WLAN has low requirements on network latency and bandwidth.
• Enterprise AP: mainly deployed in enterprise scenarios, providing wireless access services for production and office work in various industries. In most cases, a large number of APs are deployed in centralized or cloud mode, such as enterprise office, distance education, and telemedicine scenarios. The number of STAs varies depending on the application scenarios, which usually have high requirements on network latency, bandwidth, and security.

Depending on their installation scenario, APs are classified as indoor settled, indoor wall plate, or outdoor APs.

• Indoor settled APs: provide wireless network access services for indoor scenarios of a large area, such as classrooms, large offices, and shopping malls. These APs are typically ceiling mounted.
• Indoor wall plate APs: provide wireless network access services for indoor scenarios of a small area, such as dormitories, hotel guest rooms, and hospital wards. Common wall plate APs are typically wall mounted, while wall plate 86x86 APs are typically mounted on junction boxes.
• Outdoor APs: provide wireless network access services for outdoor scenarios, such as playgrounds, pedestrian streets, and amusement parks. These APs are typically wall or pole mounted, and must be highly waterproof and dustproof and offer excellent surge protection.

Additionally, there are some APs customized for industries, for example, vehicle-mounted and track-side APs for train-to-ground communication, intrinsically safe APs for underground operation, and zero-roaming distributed APs for healthcare networks.

What Are the Common Deployment Modes for Access Points?

APs are widely used in scenarios such as home Internet access, enterprise office, and shopping mall/supermarket entertainment. Typical deployment modes include centralized AC + Fit AP deployment, independent Fat AP deployment, centralized leader AP + Fit AP deployment, and cloud-based deployment.

• Centralized AC + Fit AP deployment

  The AC + Fit AP architecture is widely used for Wi-Fi network deployment in large and midsize campuses, such as shopping malls, supermarkets, hotels, and enterprise offices. The AC manages and controls all Fit APs connected to it through CAPWAP tunnels. The AC delivers configurations to Fit APs in batches, eliminating the need to configure APs one by one. This greatly reduces WLAN management and maintenance costs. Additionally, STAs can roam between Fit APs because their access authentication is centrally managed by the AC.

  In small-scale Wi-Fi coverage scenarios, only a few APs are required. If an additional AC is deployed, the WLAN cost is increased. In such a scenario, Fat APs are recommended if STA roaming is not required. If STA roaming is required, cloud APs are recommended.

• Independent Fat AP deployment

  A Fat AP can provide Wi-Fi coverage independently without the need of an additional management and control device. However, because the Fat AP controls STA access independently, STAs cannot roam between Fat APs. The STAs can use the Wi-Fi network only within the coverage area of the connected Fat AP.

  Therefore, Fat APs are typically deployed to provide small-scale Wi-Fi coverage in home or small office environments. In enterprise scenarios, the AC + Fit AP and cloud management platform + cloud AP networking modes are typically used.

• Centralized leader AP + Fit AP deployment

  The leader AP function is an extended function of Fat APs. Like an AC, a Fat AP enabled with the leader AP function can be deployed to build a WLAN together with multiple Fit APs. On this WLAN, the Fat AP manages and configures the Fit APs in a unified manner, enabling STAs to easily roam between APs. In the leader AP + Fit AP networking architecture, a Fat AP can be considered as a combination of an AC and a Fit AP. Without the leader AP function, the Fat AP can manage only its own Fit AP module. With the leader AP function configured, the Fat AP can also manage other Fit APs.

• Cloud-based deployment

  Cloud APs provide similar functions as Fat APs, and can be deployed to build small WLANs in home or small office environments. Similar to the AC + Fit AP architecture, the cloud management platform + cloud AP architecture allows cloud APs to be centrally managed and controlled by the cloud management platform. Therefore, this architecture is also applicable to large and midsize networks.

  Cloud APs are plug-and-play and are easy to deploy. They can be flexibly expanded out of space restrictions. Therefore, cloud APs are widely used in multi-branch scenarios.

Development Prospect of Access Points

Wireless technologies and products are rapidly maturing. Against this backdrop, wireless products such as mobile phones, laptops, and tablets have become integral to our daily life, work, and study. To better meet the requirements of rapidly expanding wireless networks, the Wi-Fi technology has evolved from Wi-Fi 5 to Wi-Fi 6, and more recently to Wi-Fi 7, enabling an AP to support the throughput of up to 23 Gbit/s. Moreover, a variety of IoT terminals, such as Bluetooth and RFID terminals, need to access wireless networks. As such, IoT APs are becoming increasingly popular, which can offer wireless access to IoT terminals through built-in modules and external cards. This simplifies network deployment and makes wireless networks more universal and easy to manage.

To sum up, APs will continue to develop towards higher bandwidth, faster network speeds, and more stable ubiquitous access to meet fast-growing wireless network requirements.

What AP Products Does Huawei Provide?

Huawei APs include indoor settled APs, indoor wall plate APs, outdoor APs, and four types of scenario-specific APs (zero-roaming distributed APs, intrinsically safe APs, rail transportation APs, and agile distributed APs). Depending on their capabilities, AP models are classified as standard AirEngine 5700 series APs, high-end AirEngine 6700 series APs, and flagship AirEngine 8700 series APs. For more information about Huawei APs, see Huawei WLAN Products.

In addition to offering an extensive range of Wi-Fi 6 APs, Huawei has launched next-generation Wi-Fi 7 APs. These new devices offer several advanced features, including:

• Higher bandwidth: Medical image downloads and readings can be completed within seconds, achieving speeds twice as fast as those with Wi-Fi 6.
• Enhanced experience: VIP users enjoy an uncompromised experience, and key applications run smoothly with zero interruptions.
• Higher concurrency: Up to 30 users can participate in a 4K video class simultaneously without experiencing any dizziness or motion sickness. The concurrency performance is twice that of Wi-Fi 6.
• Stronger security: Wi-Fi Shield, unique in the industry, ensures consistent Wi-Fi security for users wherever they go, preventing signal eavesdropping.

For more information about Wi-Fi 7 APs, see Huawei Wi-Fi 7 APs.