1. Background
The early network was based on the OSI (Open Systems Internet, generally called OSI Reference Model) model, which was formulated by the ISO International Standards Organization and included seven layers (application layer, presentation layer, session layer, transport layer, network layer) , Data link layer, physical layer), which is complicated and impractical, so that it attracted a lot of criticism. Therefore, at that time, a group of technicians developed a new set of protocols, TCP/IP, in order to facilitate development and improve efficiency. Protocol, in the simplified computer network OSI model, she has completed the functions specified by the fourth layer of the transport layer.
2. Concept
The TCP/IP protocol (Transmission Control Protocol), translated as the Transmission Control Protocol, is a connection-oriented, reliable, byte stream-based transport layer communication protocol. Contains four layers (application layer, transport layer, internet layer, network interface layer), but in essence, the TCP/IP protocol has only the top three layers, because the bottom network interface layer is basically the same as the general communication chain There is not much difference in the function of the road .
Application layer: Responsible for handling specific application details. Contains various application protocols, such as: Telnet remote login, FTP file transfer protocol, SMTP simple mail transfer protocol, SNMP simple network management protocol.
Transport layer: Provides flow control, error control and confirmation services for the network. In the TCP/IP protocol suite, there are two different transmission protocols: TCP and UDP, which will be explained later.
Internet layer: Provides logical addressing independent of hardware to realize the conversion between physical address and logical address. Internet layer (also called network layer) protocols include IP protocol, ICMP protocol and OGMP protocol (Internet Group Management Protocol).
Network interface layer: usually includes the device driver in the operating system and the corresponding network interface card in the computer, which together deal with the details of the physical interface with the cable or other human-protected transmission media. The corresponding equipment includes transmission media, network cards, and switches.
3. TCP and UDP
TCP and UDP are the two most famous transport layer protocols. Both use IP as the network layer protocol. Although both TCP and UDP use the same network layer (IP), TCP provides completely different services to the application layer than UDP.
(1) TCP
TCP, Transmission Control Protocol, connection-oriented protocol, reliable byte stream service. Connection-oriented means that two applications using TCP (usually a client and a server) must establish a TCP connection before exchanging data with each other.
Features: 1)Only supports one-to-one transmission (end-to-end transmission); 2)Unlimited data size; 3)Establish a connection channel Slow speed, but high reliability.
(2) UDP
User Datagram Protocol is a connectionless transport layer protocol in the OSI reference model. It provides simple and unreliable transaction-oriented information transmission services. UDP provides connectionless communication and is suitable for transmitting a small amount of data at a time. UDP packets are not reliable. Guarantee, sequence guarantee and flow control fields, etc., have poor reliability. However, because the UDP protocol has fewer control options, the delay in data transmission is small, and the data transmission efficiency is high. It is suitable for applications that do not require high reliability, or applications that can guarantee reliability, such as DNS, TFTP, and SNMP.
① Features: 1) One-to-one, one-to-many, many-to-one and many-to-many interactive communication is possible; 2) Fast speed, but low reliability; 3) The data has a size limit (64k) 4) No need to establish a connection
② application: Generally used in real-time chats such as QQ and WeChat.
（3）The difference between TCP and UDP
1) TCP is connection-oriented (such as dialing to establish a connection before making a call), UDP is connectionless, that is, there is no need to establish a connection before sending data.
2) TCP provides reliable services, that is to say, the data transmitted through the TCP connection has no errors, no loss, no repetition, and arrives in order; TCP realizes reliable transmission through checksum retransmission control, sequence number identification, sliding window, and confirmation response . For example, the retransmission control when the packet is lost, the order can also be controlled for the out-of-order sub-packets. UDP does its best to deliver, that is, reliable delivery is not guaranteed.
3) UDP has better real-time performance, higher work efficiency than TCP, suitable for high-speed transmission and real-time communication or broadcast communication.
4) Each TCP connection can only be point-to-point, UDP supports one-to-one, one-to-many, many-to-one and many-to-many interactive communication.
5) TCP requires more system resources, while UDP requires less system resources.
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How far(long) the transmitter cover?
The transmission range depends on many factors. The true distance is based on the antenna installing height , antenna gain, using environment like building and other obstructions , sensitivity of the receiver, antenna of the receiver . Installing antenna more high and using in the countryside , the distance will much more far.
EXAMPLE 5W FM Transmitter use in the city and hometown:
I have a USA customer use 5W fm transmitter with GP antenna in his hometown ,and he test it with a car, it cover 10km(6.21mile).
I test the 5W fm transmitter with GP antenna in my hometown ,it cover about 2km(1.24mile).
I test the 5W fm transmitter with GP antenna in Guangzhou city ,it cover about only 300meter(984ft).
Below are the approximate range of different power FM Transmitters. ( The range is diameter )
0.1W ~ 5W FM Transmitter ：100M ~1KM
5W ~15W FM Ttransmitter : 1KM ~ 3KM
15W ~ 80W FM Transmitter : 3KM ~10KM
80W ~500W FM Transmitter : 10KM ~30KM
500W ~1000W FM Transmitter : 30KM ~ 50KM
1KW ~ 2KW FM Transmitter : 50KM ~100KM
2KW ~5KW FM Transmitter : 100KM ~150KM
5KW ~10KW FM Transmitter : 150KM ~200KM
How to contact us for the transmitter?
Call me +8618078869184 OR
Email me [email protected]
1.How far you want to cover in diameter ?
2.How tall of you tower ?
3.Where are you from ?
And we will give you more professional advice.
About Us
FMUSER.ORG is a system integration company focusing on RF wireless transmission / studio video audio equipment / streaming and data processing .We are providing everything from advice and consultancy through rack integration to installation, commissioning and training.
We offer FM Transmitter, Analog TV Transmitter, Digital TV transmitter, VHF UHF Transmitter, Antennas, Coaxial Cable Connectors, STL, On Air Processing, Broadcast Products for the Studio, RF Signal Monitoring, RDS Encoders, Audio Processors and Remote Site Control Units, IPTV Products, Video / Audio Encoder / Decoder, designed to meet the needs of both large international broadcast networks and small private stations alike.
Our solution has FM Radio Station / Analog TV Station / Digital TV Station / Audio Video Studio Equipment / Studio Transmitter Link / Transmitter Telemetry System / Hotel TV System / IPTV Live Broadcasting / Streaming Live Broadcast / Video Conference / CATV Broadcasting system.
We are using advanced technology products for all the systems, because we know the high reliability and high performance are so important for the system and solution . At the same time we also have to make sure our products system with a very reasonable price.
We have customers of public and commercial broadcasters, telecom operators and regulation authorities , and we also offer solution and products to many hundreds of smaller, local and community broadcasters .
FMUSER.ORG has been exporting more than 15 years and have clients all over the world. With 13 years experience in this field ,we have a professional team to solve customer's all kinds of problems. We dedicated in supplying the extremely reasonable pricing of professional products & services. Contact email : [email protected]
Our Factory
We have modernization of the factory . You are welcome to visit our factory when you come to China.
At present , there are already 1095 customers around the world visited our Guangzhou Tianhe office . If you come to China , you are welcome to visit us .
At Fair
This is our participation in 2012 Global Sources Hong Kong Electronics Fair . Customers from all over the world finally have a chance to get together.
Where is Fmuser ?
You can search this numbers " 23.127460034623816,113.33224654197693 " in google map , then you can find our fmuser office .
FMUSER Guangzhou office is in Tianhe District which is the center of the Canton . Very near to the Canton Fair , guangzhou railway station, xiaobei road and dashatou , only need 10 minutes if take TAXI . Welcome friends around the world to visit and negotiate .
Contact: Sky Blue
Cellphone: +8618078869184
WhatsApp: +8618078869184
Wechat: +8618078869184
E-mail: [email protected]
QQ: 727926717
Skype: sky198710021
Address: No.305 Room HuiLan Building No.273 Huanpu Road Guangzhou China Zip:510620
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English: We accept all payments , such as PayPal, Credit Card, Western Union, Alipay, Money Bookers, T/T, LC, DP, DA, OA, Payoneer, If you have any question , please contact me [email protected] or WhatsApp +8618078869184
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PayPal.  www.paypal.com
We recommend you use Paypal to buy our items ,The Paypal is a secure way to buy on internet .
Every of our item list page bottom on top have a paypal logo to pay.
Credit Card.If you do not have paypal,but you have credit card,you also can click the Yellow PayPal button to pay with your credit card.
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But if you have not a credit card and not have a paypal account or difficult to got a paypal accout ,You can use the following:
Western Union.  www.westernunion.com
Pay by Western Union to me :
First name/Given name: Yingfeng
Last name/Surname/ Family name: Zhang
Full name: Yingfeng Zhang
Country: China
City: Guangzhou
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T/T . Pay by T/T (wire transfer/ Telegraphic Transfer/ Bank Transfer)
First BANK INFORMATION (COMPANY ACCOUNT):
SWIFT BIC: BKCHHKHHXXX
Bank name: BANK OF CHINA (HONG KONG) LIMITED, HONG KONG
Bank Address: BANK OF CHINA TOWER, 1 GARDEN ROAD, CENTRAL, HONG KONG
BANK CODE: 012
Account Name : FMUSER INTERNATIONAL GROUP LIMITED
Account NO. : 012-676-2-007855-0
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Second BANK INFORMATION (COMPANY ACCOUNT):
Beneficiary: Fmuser International Group Inc
Account Number: 44050158090900000337
Beneficiary's Bank: China Construction Bank Guangdong Branch
SWIFT Code: PCBCCNBJGDX
Address: NO.553 Tianhe Road, Guangzhou, Guangdong,Tianhe District, China
**Note: When you transfer money to our bank account, please DO NOT write anything in the remark area, otherwise we won't be able to receive the payment due to government policy on international trade business.
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* It will be sent in 1-2 working days when payment clear.
* We will send it to your paypal address. If you want to change address, please send your correct address and phone number to my email [email protected]
* If the packages is below 2kg,we will be shipped via post airmail, it will take about 15-25days to your hand.
If the package is more than 2kg,we will ship via EMS , DHL , UPS, Fedex fast express delivery,it will take about 7~15days to your hand.
If the package more than 100kg , we will send via DHL or air freight. It will take about 3~7days to your hand.
All the packages are form China guangzhou.
* Package will be sent as a "gift" and declear as less as possible,buyer don't need to pay for "TAX".
* After ship, we will send you an E-mail and give you the tracking number.
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For Warranty .
Contact US--->>Return the item to us--->>Receive and send another replace .
Name: Liu xiaoxia
Address: 305Fang HuiLanGe HuangPuDaDaoXi 273Hao TianHeQu Guangzhou China.
ZIP:510620
Phone: +8618078869184
Please return to this address and write your paypal address,name,problem on note: |
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