To use wireless hotspots, your computer must be equipped with Wi-Fi-certified radio devices, for example, an external PC Card or integrated wireless LAN connection capability (such as provided by Intel or the mobile technology of the company ). In addition, you also need to select a wireless service provider as the ISP, usually using T1speed to provide paid wireless Internet access services.
2. What is a wireless network?
Generally speaking, the so-called wireless network, as its name implies, uses radio waves as data transmission. In terms of application, it is similar to the wired network, the biggest difference between the two is that the media for data transmission is different. In addition, because it is wireless, the flexibility of hardware setup or use is much more advantageous than that of wired networks.
3. What are the advantages of wireless networks compared with wired networks?
The flexibility and convenience of using it are not suitable for wired networks. In terms of cost, it can save a considerable cost for wiring and modification and decoration, basically, the space used is much more elastic.
4. Does wireless networks affect the human body?
Because the transmit power of wireless networks is much weaker than that of other mobile phones, the transmit power of wireless networks is about 20 ~ 70 mW, and the launch power of the Big Brother mobile phone is about mW, and the method of use is not like the mobile phone is generally directly exposed to the human body, so there is no security considerations.
5. What are the basic requirements for a wireless network?
Generally, the basic configuration of a wireless network is a wireless network card and a bridge (AP). In this way, you can share network resources in a wireless mode with the existing wired architecture.
6. Will wireless networks be disturbed or affect the operation of other devices?
Basically, the frequency band used by wireless networks is within the high frequency range of ISM 2.4GHz. Electrical equipment used in daily life, office, and so on will not interfere with each other because of frequent differences, in addition, the wireless network itself has 12 channels available for adjustment, so there is no need to worry about the phenomenon of natural interference.
7. What is the ISM frequency band?
ISM frequency band, divided into industry (902-928 MHz), Scientific Research (2.42-2.4835 GHz) and medical (5.725-5.850 GHz) --- by the US Federal Communications Commission (FCC) assigned radio frequency bands without license (power cannot exceed 1 W ). Recently (1997.1) approved for wireless LAN (WLAN) is a medical frequency band.
8. What is Spread Spectrum )?
The frequency Zhan technology is divided into two main methods: frequency hopping technology and direct sequence. These two technologies are used by the military in the Second World War. They aim to maintain the stability and confidentiality of communication signals in a harsh war environment. For a non-specific receiver, the beat signal produced by Spread Spectrum is only impulse noise. Therefore, it is a secure communication technology.
9. What is Frequency Hopping (Frequency-Hopping Spread Spectrum )?
Frequency-Hopping Spread Spectrum; FHSS receives signals transmitted by narrow-Frequency carriers of a specific type at both ends of synchronization and at the same time, for a non-specific receiver, the hop signal generated by FHSS is only impulse noise. FHSS signals can be specially designed to avoid noise or non-repetitive channels of One-to-One channels, and these frequency hopping signals must comply with FCC requirements, the maximum interval between 75 or more frequency hopping signals and the next frequency (Dwell Time) is 400 ms.
10. What is Direct Sequence Spread Spectrum )?
Direct Sequence Spread Spectrum; DSSS is to convert the original signal "1" or "0 」, more than 10 chips are used to represent the "1" or "0" bits, making the original high power and narrow frequency a low power frequency with a wide bandwidth. The number of chips used by each bit is called Spreading chips. A higher Spreading chips can increase noise resistance, while a lower Spreading Ration can increase the number of users. Basically, the Spreading Ration in DSSS is quite small. For example, the number of Spreading rations used by almost all wireless local area network products of 2 to 4 GHz is less than 20. In the IEEE 802.11 standard, the Spreading Ration is only 11, but the FCC stipulates that it must be greater than 10. In the experiment, the best Spreading Ration is about 100.
11. How wide is the coverage of wireless networks?
Generally, the coverage range of a wireless network depends on whether the environment is open or not. If an external antenna is not added, it is about 250 M in the field of view. If it is a semi-open space, the area with a compartment is about 35 ~ About 50 M. Of course, if an external antenna is added, the distance can be further reached, which is determined by the gain of the antenna itself. Therefore, it must be planned based on the customer's needs.
12. What is the confidentiality of wireless networks during use?
Basically, GEMPLEX's wireless network technology uses the DSSS System to defend against eavesdropping. In addition, with the dual protection of WEP40bits, its security is quite comprehensive.
13. What is Access Point )?
An Access Point is generally called a Network Bridge. As its name suggests, it serves as a bridge between a traditional wired local network and a wireless local network, therefore, any PC with a wireless network card can share resources of a wired local area network or even a wide area network through an AP. In addition, the AP also has the network management function, which can be used to control PCs connected with wireless network cards.
14. How many workstations can Access Point support at the same time?
In theory, a class c can be supported, but in order to make the workstation have sufficient bandwidth available, it is recommended that an AP support about 20 ~ The workstation around 30 is in the optimal state.
15. What is the Roaming function?
Similar to a large volume, Wireless Network Workstations can roam between different base stations, as long as the ESSID of the AP group is defined, then, the wireless network workstation can freely roam in the area where radio waves can cover.
16. If a wireless network device is set up outdoors, how can it prevent lightning strikes?
Basically, lightning arresters can be configured in wireless networks. This device can be purchased and installed on wireless network devices to cause system damage due to sudden surges.
17. What is Access Control?
Basically, each wireless network card has a unique set of hardware addresses, the so-called MAC address. Access Control table allows you to define certain cards to log on to this AP, and some cards are denied to log on, in this way, the control mechanism can be achieved to avoid non-related personnel from logging on to the network at will and stealing resources.
18. What is ASBF?
ASBF (Automatic Scale Back Functionality) is a unique feature of Gemplex AP, which ensures that WLAN is always in the optimal online quality. In addition, it also provides wireless network adapters that support multiple vendors, however, its Nic must be designed in compliance with IEEE 802.11 specifications.
19. What is Power Management?
Because Notebook needs to be charged after about 2 hours, if other peripheral devices are used at the same time, it will certainly consume more power, therefore, this function is used to effectively manage the power consumed by wireless network cards. In other words, it can control when DATA sending or refreshing is in the "Wake up status ", otherwise, it is in power down mode.
20. Does the length of the feeder used by the antenna affect the transmission quality?
Generally, the length, material, and impedance matching of the feeder used by the antenna will affect the signal to a certain extent, and the most obvious is gain attenuation. Generally, the length of 20 feet degrades the signal by about 1.2dBi, while the average attenuation of 8 DBI reduces the original transmission distance by about half, therefore, the length and quality of feeder cannot be ignored in the application of wireless products.
21. What is Ad-hoc?
A special wireless network application mode. A group of computers connect to a wireless network card to connect to each other and share resources without accessing Point.
22. What is Infrastructure?
An application model that integrates the wired and wireless LAN architectures. This architecture allows you to share network resources. This application uses Access Point.
23. What is BSS?
A special application of Ad-hoc LAN, called Basic Service Set (BSS). A group of computers can Set the same BSS name to form a group, that is, BSSID.
24. What is ESS?
An Infrastructure application, one or more BSS, can be defined as an Extended Service Set (ESS). Users can roaming on ESS and access any data in BSSs, the Access Points must set the same ESSID and channel to allow roaming.
25. What is SNMP?
"Simple Network Management Protocol", a Network Management communication Protocol, through SNMP software, you can connect to a device that supports SNMP and collect all the information of the device for other integrated applications. Gemplex Wireless LAN product supports this feature.
26. What is WEP?
"Wired Equivalent Protection" is a method of encrypting data. The encryption of WEP 40bits is the standard specification of IEEE 802.11. Through the processing of WEP, we can make our data more secure during transmission. Article entry: aaadxmmm responsible editor: aaadxmmm
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