Yingke virtual and currency exchange
Publish: 2021-04-25 05:46:15
1. Although I don't know much about games, some people can make money by playing games, and it's not illegal or professional.
2. The local exchange supporting the secondary market of legal currency / digital currency is one of the best integrated resources for the head exchange in the global expansion route. It is not only concive to the spread of the head exchange in the local market, but also can solve the problem of legal currency into gold with high efficiency and low cost. It is expected that the head exchange will graally set off an upsurge of investment and integration of local legal currency exchange
in addition to the direct exchange trading, the cash in and out of the legal currency can also be traded over the counter. In fact, the volume of OTC trading is very large. According to Tabb Research Report, OTC market is 2-3 times of the volume of OTC trading. Because of the exchange trading, because of the existence of brush volume, the actual OTC trading volume is even higher. This paper focuses on the existing value of the OTC market, who are the main buyers and sellers, the distribution of the types of gold channels, the distribution of the types of gold coins, and how the exchange should expand the channels of legal coins.
in addition to the direct exchange trading, the cash in and out of the legal currency can also be traded over the counter. In fact, the volume of OTC trading is very large. According to Tabb Research Report, OTC market is 2-3 times of the volume of OTC trading. Because of the exchange trading, because of the existence of brush volume, the actual OTC trading volume is even higher. This paper focuses on the existing value of the OTC market, who are the main buyers and sellers, the distribution of the types of gold channels, the distribution of the types of gold coins, and how the exchange should expand the channels of legal coins.
3. The first generation IPFs miner "hummingbird H1" has been developed and is expected to be sold in early April. You can pay more attention.
4. I borrow 23000 on it and freeze it when I withdraw cash. I haven't got any money. I have to repay the loan every month. I say I call the police and they say it's up to me.
5. It's hard to say that the ability of the team is poor. It used to be COFCO futures, but now it seems to have gone to Zhongtian. It's an asset management team with perfect investment and research system, fine division of labor and high degree of specialization in the domestic futures field. You can learn more about it. If you agree with my answer, I hope you can help me adopt it
6. This belongs to the swindler platform, not credible, more unreliable, I encountered the same situation as you, fortunately in time to find someone to help save the loss!
7. If you need to buy financial procts, you can also learn about the financial procts sold by CMB in your city. You can go to CMB's homepage, click the page of financial procts - personal financial procts to view, or search and classify the financial procts you need
warm tips: please read the proct manual carefully before purchasing.
warm tips: please read the proct manual carefully before purchasing.
8. 1. MOCA technology
features of MOCA:
use frequency band 800mhz-1500mhz, choose 1GHz below, convenient wiring
each channel bandwidth is 50MHz, 15 channels can be selected, physical layer rate can reach 270mbps, data link layer rate can reach 130mbps
use OFDM molation, TDMA / TDD
advantages of MOCA:
alliance standard, high bandwidth, can pass through branch distributor, In North America, MOCA has a large scale of application, but its disadvantages are as follows:
the price of a single chip manufacturer is still on the high side, and its procts are not mature enough.
the price of MOCA equipment drops rapidly, and there are more manufacturers.
MOCA application topology
2 (1) Coaxial Wi-Fi technology
features of coaxial Wi-Fi:
Wi Fi used to be the alias of IEEE802.11b wireless access network
IEEE 802.11g works at 2.400-2.482ghz, adopts OFDM molation, the physical layer transmission rate is 54Mbps, and the data link layer speed is about 25mbps.
the main problem of using Wi Fi is that the wireless signal attenuation is too fast, The loss can be effectively reced by transmitting it through coaxial cable.
there are two ways to rece the frequency of Wi Fi through coaxial cable.
it is worth noting that the preliminary standard of new ieee802.11n has been passed. The throughput of 108mbps can be ensured up to 300mbps.
advantages of coaxial Wi-Fi:
full standard application, mature equipment and high reliability Low cost
disadvantages of coaxial Wi-Fi:
all branch distributors need to be replaced
(2) down frequency coaxial Wi-Fi technology
features of down frequency coaxial Wi-Fi:
rece the frequency to 900MHz without replacing the existing network equipment
like Moca, it can pass through the branch distributor, but not through the amplifier
because the bandwidth is lower than Moca, in order to ensure the bandwidth, Therefore, a WiFi head end usually has 12 cable TV users, and an ONU has four Wi-Fi heads.
advantages of down frequency coaxial Wi-Fi:
mature technology and low price, which is the lowest cost of all active EOC technologies. Compared with passive EOC, it has the advantage of rolling investment.
disadvantages of down frequency coaxial Wi-Fi:
down frequency is a non-standard way, Hpna3.0 technology
hpna3.0 features:
the frequency band is 12mhz-28mhz, which is the same as the existing CATV network structure
the physical layer rate is 128mbps, and the data link layer rate can reach 80mbps
fdqam molation is adopted, and 2-8 carriers with different frequencies are set on the frequency axis to transmit the same data at the same time, Compared with traditional QAM molation, hpna3.0 has stronger anti-interference ability and better performance. Advantages:
ITU's international standard, higher bandwidth, can pass through branch distributor and amplifier. Disadvantages:
there are not many chip manufacturers, and the current price is still on the high side. PLC technology
PLC features:
2001, Homeplug 1.0 14mbps
2004, Homeplug turbo 85mbps
2005, Homeplug AV 200Mbps
frequency band: 2 ~ 28MHz, OFDM molation (84), maximum link attenuation 60dB, strong anti noise performance
data link layer data rate 30mbps, Homeplug AV up to 150Mbps
PLC advantages:
mature technology, low price, alliance standard, IEEE standard is being developed, and anti noise, anti multipath
PLC disadvantages:
200m chip is not mature, The bandwidth of 45m chip is only the same as Wi-Fi. Recently, SpeedBit's 224m chip has launched
PLC application topology
5. Baseband EOC Technology
baseband EOC features:
link layer fully follows 802.3x, point-to-point connection, and all electrical characteristics are close to LAN mode
bipolar differential signal / unipolar signal, 75 Ω/ one hundred Ω Bandwidth: IP data: 0.5-65mhz
advantages of baseband EOC:
low cost per line, more manufacturers, and a certain scale of application in China
disadvantages of baseband EOC:
it can not pass branch allocator, only supports point-to-point star distribution network, and each line bandwidth is fixed 10m, so it must be put into place at one time, It can't realize rolling investment
2. Non standard technology
1. EPCN technology
EPCN features:
a home technology introced by Huasan, which adopts Broadcom's RF chip and is based on point to multipoint baseband transmission technology
EPCN advantages: low cost, can pass through branch allocator, and does not need to change the existing network
EPCN disadvantages: non standard technology, Proct application time is not long
EPCN application topology
2. BIOC technology
features of BIOC:
a home technology launched by Hangzhou leiketong Co., Ltd., a technology based on WiFi frequency rection
advantages of BIOC:
low cost, through branch allocator, there is no need to change the existing network
disadvantages of BIOC:
non-standard technology, The proct has not been used for a long time
e to the limited transmission distance of Wi-Fi technology, Raycom has launched its own amplifier, extender and other equipment
3. Uclink technology
features of uclink:
a new data access solution launched by Huawei, The system consists of the following moles:
uc8001: data access device: uc8001 is located between the user terminal and the convergence device, and it is the network node of the uclink integrated access system.
uc6201: data user terminal: realizes the mutual transformation between the RF data and the standard Ethernet data.
umix data RF mixer: used to input the data of uc8001 into the radio frequency The output signal is mixed with CATV RF signal and transmitted in the coaxial distribution network.
ujump data RF Jumper: it is used to bridge the RF amplifier to ensure the bidirectional transmission of uclink data RF signal; Actual test results: the actual transmission link attenuation of uclink is about 85dB (for field type uc8001, this link refers to the test data between the hybrid port and uc6201, including the insertion loss of the mixer). Considering a certain link margin (5dB), the actual attenuation link loss is 80dB, In addition, uclink system supports 45dB dynamic line attenuation under the condition of not exceeding Lmax, that is, the allowable range of actual line attenuation L is: l = 35dbi80db.
advantages of uclink:
good network adaptability
for the existing CATV network, simple bidirectional transformation is carried out, The data access function can be realized by installing the corresponding uclink equipment.
the cost of single channel is lower than that of similar procts, and the cost advantage is especially obvious when the user access rate is low.
the initial investment is small, the engineering quantity is small, and the business can be carried out rapidly, To ensure the effectiveness of investment.
can support broadband services
disadvantages of uclink:
weak business support ability, difficult to support three networks in one
user sharing 10m, single user broadband less than 1m
small broadband demand, can only achieve simple broadband Internet services
only belongs to a transitional technology
schematic diagram of uclink for hub bridging scheme
4 Cableran technology
cableran features:
Putian E-vision introces an access scheme, which is a broadband access system based on one-way cable TV network. The cableran access equipment consists of front-end MAS, intelligent port I / O and network management software;, Coverage of 5km, maximum access to 64 users
downlink band 40-80mhz, QAM256, maximum 48mbps
downlink transmission level: 50dbmv; Receiving level: - 10dbmv ~ 40dbmv
uplink band: 5 ~ 36MHz, QPSK, qam16, maximum 12mbps
uplink transmitting level: maximum 48dbmv (adaptive) receiving level: - 10dbmv ~ 15dbmv
MAS is a multi-mode access IP gateway device, which can restore I / O of front-end device to IP signal, Each front MAS can support 64 port I / O. the front MAS can be conveniently placed in buildings or optical nodes. The intelligent port I / O device is a signal conversion device, which can molate the IP signal from the front MAS on the coaxial cable, Restore to the standard Ethernet signal in the form of RJ45 or USB interface.
only the intelligent terminal I / O is needed to replace the existing ordinary set-top box, and a MAS small office is added between the trunk line and the building.
cableran technology has an uplink bandwidth of 10mbit / s and a downlink bandwidth of 48mbit / s. It takes up 5 ~ 65Mhz frequency part, of which 5 ~ 36MHz is used for uplink, 40 ~ 65 MHz is the downlink band. The downlink uses 16 / 64 / 256qam molation, and the uplink uses QPSK and 16QAM molation.
cableran network structure diagram
these non-standard procts have their own characteristics, do not have outstanding cost performance advantages, and have more technical and commercial risks
3. Comparison of various EOC technologies
1. Bandwidth comparison (data rate)
MoCA 130mbps
hpna3.080mbps, 3.1 standard will be higher
PLC 30mbps, Homeplug AV standard will be higher
Wi-Fi 25mbps, 802.11n standard will be higher
BIOC 25mbps
EPCN 10Mbps, next generation procts will be higher
& nbsp; Baseband EOC 10Mbps
2. Cost comparison
MOCA is the highest, but the recent price decline is fast
hpna3.0 is on the high side
PLC is medium
Wi-Fi is low
IOC price is not clear
EPCN price strategy is not clear, proct cost is low
baseband EOC price per line is low, but the implicit cost is relatively high
3. Compatibility with existing network
MOCA compatibility is better, The compatibility of hpna3.0 is the best, the compatibility between hpna3.0 and PLC is better, the compatibility between hpna3.0 and PLC is better, the compatibility between hpna3.0 and PLC is better, the compatibility between hpna3.0 and PLC is better, the compatibility between hpna3.0 and PLC is better, the compatibility between hpna3.0 and PLC is better, and the compatibility between hpna3.0 and PLC is better, It can pass through branch distributor but not amplifier
the compatibility of EPCN is better, it can pass through branch distributor but not amplifier
the compatibility of baseband EOC is poor, it can not pass through branch distributor and amplifier
4, maturity comparison
MOCA is more mature, and it has large-scale application in North America
hpna3.0 is more mature, With the support of ITU standard, the application of PLC in power line is mature, and the application in radio and television field is just beginning.
Wi-Fi procts are very mature, but the application of frequency rection part is just beginning.
procts launched by BIOC in 2006 are just beginning to be applied in China.
procts launched by EPCN in 2007 have been partially applied in China
features of MOCA:
use frequency band 800mhz-1500mhz, choose 1GHz below, convenient wiring
each channel bandwidth is 50MHz, 15 channels can be selected, physical layer rate can reach 270mbps, data link layer rate can reach 130mbps
use OFDM molation, TDMA / TDD
advantages of MOCA:
alliance standard, high bandwidth, can pass through branch distributor, In North America, MOCA has a large scale of application, but its disadvantages are as follows:
the price of a single chip manufacturer is still on the high side, and its procts are not mature enough.
the price of MOCA equipment drops rapidly, and there are more manufacturers.
MOCA application topology
2 (1) Coaxial Wi-Fi technology
features of coaxial Wi-Fi:
Wi Fi used to be the alias of IEEE802.11b wireless access network
IEEE 802.11g works at 2.400-2.482ghz, adopts OFDM molation, the physical layer transmission rate is 54Mbps, and the data link layer speed is about 25mbps.
the main problem of using Wi Fi is that the wireless signal attenuation is too fast, The loss can be effectively reced by transmitting it through coaxial cable.
there are two ways to rece the frequency of Wi Fi through coaxial cable.
it is worth noting that the preliminary standard of new ieee802.11n has been passed. The throughput of 108mbps can be ensured up to 300mbps.
advantages of coaxial Wi-Fi:
full standard application, mature equipment and high reliability Low cost
disadvantages of coaxial Wi-Fi:
all branch distributors need to be replaced
(2) down frequency coaxial Wi-Fi technology
features of down frequency coaxial Wi-Fi:
rece the frequency to 900MHz without replacing the existing network equipment
like Moca, it can pass through the branch distributor, but not through the amplifier
because the bandwidth is lower than Moca, in order to ensure the bandwidth, Therefore, a WiFi head end usually has 12 cable TV users, and an ONU has four Wi-Fi heads.
advantages of down frequency coaxial Wi-Fi:
mature technology and low price, which is the lowest cost of all active EOC technologies. Compared with passive EOC, it has the advantage of rolling investment.
disadvantages of down frequency coaxial Wi-Fi:
down frequency is a non-standard way, Hpna3.0 technology
hpna3.0 features:
the frequency band is 12mhz-28mhz, which is the same as the existing CATV network structure
the physical layer rate is 128mbps, and the data link layer rate can reach 80mbps
fdqam molation is adopted, and 2-8 carriers with different frequencies are set on the frequency axis to transmit the same data at the same time, Compared with traditional QAM molation, hpna3.0 has stronger anti-interference ability and better performance. Advantages:
ITU's international standard, higher bandwidth, can pass through branch distributor and amplifier. Disadvantages:
there are not many chip manufacturers, and the current price is still on the high side. PLC technology
PLC features:
2001, Homeplug 1.0 14mbps
2004, Homeplug turbo 85mbps
2005, Homeplug AV 200Mbps
frequency band: 2 ~ 28MHz, OFDM molation (84), maximum link attenuation 60dB, strong anti noise performance
data link layer data rate 30mbps, Homeplug AV up to 150Mbps
PLC advantages:
mature technology, low price, alliance standard, IEEE standard is being developed, and anti noise, anti multipath
PLC disadvantages:
200m chip is not mature, The bandwidth of 45m chip is only the same as Wi-Fi. Recently, SpeedBit's 224m chip has launched
PLC application topology
5. Baseband EOC Technology
baseband EOC features:
link layer fully follows 802.3x, point-to-point connection, and all electrical characteristics are close to LAN mode
bipolar differential signal / unipolar signal, 75 Ω/ one hundred Ω Bandwidth: IP data: 0.5-65mhz
advantages of baseband EOC:
low cost per line, more manufacturers, and a certain scale of application in China
disadvantages of baseband EOC:
it can not pass branch allocator, only supports point-to-point star distribution network, and each line bandwidth is fixed 10m, so it must be put into place at one time, It can't realize rolling investment
2. Non standard technology
1. EPCN technology
EPCN features:
a home technology introced by Huasan, which adopts Broadcom's RF chip and is based on point to multipoint baseband transmission technology
EPCN advantages: low cost, can pass through branch allocator, and does not need to change the existing network
EPCN disadvantages: non standard technology, Proct application time is not long
EPCN application topology
2. BIOC technology
features of BIOC:
a home technology launched by Hangzhou leiketong Co., Ltd., a technology based on WiFi frequency rection
advantages of BIOC:
low cost, through branch allocator, there is no need to change the existing network
disadvantages of BIOC:
non-standard technology, The proct has not been used for a long time
e to the limited transmission distance of Wi-Fi technology, Raycom has launched its own amplifier, extender and other equipment
3. Uclink technology
features of uclink:
a new data access solution launched by Huawei, The system consists of the following moles:
uc8001: data access device: uc8001 is located between the user terminal and the convergence device, and it is the network node of the uclink integrated access system.
uc6201: data user terminal: realizes the mutual transformation between the RF data and the standard Ethernet data.
umix data RF mixer: used to input the data of uc8001 into the radio frequency The output signal is mixed with CATV RF signal and transmitted in the coaxial distribution network.
ujump data RF Jumper: it is used to bridge the RF amplifier to ensure the bidirectional transmission of uclink data RF signal; Actual test results: the actual transmission link attenuation of uclink is about 85dB (for field type uc8001, this link refers to the test data between the hybrid port and uc6201, including the insertion loss of the mixer). Considering a certain link margin (5dB), the actual attenuation link loss is 80dB, In addition, uclink system supports 45dB dynamic line attenuation under the condition of not exceeding Lmax, that is, the allowable range of actual line attenuation L is: l = 35dbi80db.
advantages of uclink:
good network adaptability
for the existing CATV network, simple bidirectional transformation is carried out, The data access function can be realized by installing the corresponding uclink equipment.
the cost of single channel is lower than that of similar procts, and the cost advantage is especially obvious when the user access rate is low.
the initial investment is small, the engineering quantity is small, and the business can be carried out rapidly, To ensure the effectiveness of investment.
can support broadband services
disadvantages of uclink:
weak business support ability, difficult to support three networks in one
user sharing 10m, single user broadband less than 1m
small broadband demand, can only achieve simple broadband Internet services
only belongs to a transitional technology
schematic diagram of uclink for hub bridging scheme
4 Cableran technology
cableran features:
Putian E-vision introces an access scheme, which is a broadband access system based on one-way cable TV network. The cableran access equipment consists of front-end MAS, intelligent port I / O and network management software;, Coverage of 5km, maximum access to 64 users
downlink band 40-80mhz, QAM256, maximum 48mbps
downlink transmission level: 50dbmv; Receiving level: - 10dbmv ~ 40dbmv
uplink band: 5 ~ 36MHz, QPSK, qam16, maximum 12mbps
uplink transmitting level: maximum 48dbmv (adaptive) receiving level: - 10dbmv ~ 15dbmv
MAS is a multi-mode access IP gateway device, which can restore I / O of front-end device to IP signal, Each front MAS can support 64 port I / O. the front MAS can be conveniently placed in buildings or optical nodes. The intelligent port I / O device is a signal conversion device, which can molate the IP signal from the front MAS on the coaxial cable, Restore to the standard Ethernet signal in the form of RJ45 or USB interface.
only the intelligent terminal I / O is needed to replace the existing ordinary set-top box, and a MAS small office is added between the trunk line and the building.
cableran technology has an uplink bandwidth of 10mbit / s and a downlink bandwidth of 48mbit / s. It takes up 5 ~ 65Mhz frequency part, of which 5 ~ 36MHz is used for uplink, 40 ~ 65 MHz is the downlink band. The downlink uses 16 / 64 / 256qam molation, and the uplink uses QPSK and 16QAM molation.
cableran network structure diagram
these non-standard procts have their own characteristics, do not have outstanding cost performance advantages, and have more technical and commercial risks
3. Comparison of various EOC technologies
1. Bandwidth comparison (data rate)
MoCA 130mbps
hpna3.080mbps, 3.1 standard will be higher
PLC 30mbps, Homeplug AV standard will be higher
Wi-Fi 25mbps, 802.11n standard will be higher
BIOC 25mbps
EPCN 10Mbps, next generation procts will be higher
& nbsp; Baseband EOC 10Mbps
2. Cost comparison
MOCA is the highest, but the recent price decline is fast
hpna3.0 is on the high side
PLC is medium
Wi-Fi is low
IOC price is not clear
EPCN price strategy is not clear, proct cost is low
baseband EOC price per line is low, but the implicit cost is relatively high
3. Compatibility with existing network
MOCA compatibility is better, The compatibility of hpna3.0 is the best, the compatibility between hpna3.0 and PLC is better, the compatibility between hpna3.0 and PLC is better, the compatibility between hpna3.0 and PLC is better, the compatibility between hpna3.0 and PLC is better, the compatibility between hpna3.0 and PLC is better, the compatibility between hpna3.0 and PLC is better, and the compatibility between hpna3.0 and PLC is better, It can pass through branch distributor but not amplifier
the compatibility of EPCN is better, it can pass through branch distributor but not amplifier
the compatibility of baseband EOC is poor, it can not pass through branch distributor and amplifier
4, maturity comparison
MOCA is more mature, and it has large-scale application in North America
hpna3.0 is more mature, With the support of ITU standard, the application of PLC in power line is mature, and the application in radio and television field is just beginning.
Wi-Fi procts are very mature, but the application of frequency rection part is just beginning.
procts launched by BIOC in 2006 are just beginning to be applied in China.
procts launched by EPCN in 2007 have been partially applied in China
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