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Frequently asked questions of MicroLink dLAN Here you find all answers to your “direct LAN” questions.
Question: What is dLAN? Answer: dLAN means "direct LAN", i. e. "directly networked". Question: Does dLAN stand for Internet via power supply? Answer: Yes and No! You can install your network that way that you can use your ADSL access on all power sockets. However, Internet isn't realized via the power line but via a separate ADSL modem. Question: Are dLAN products compatible to HomePlug devices of other manufacturers? Answer: To obtain an optimum performance and usability, we recommend to use devolo products. They are tested and proven on interoperability. Furthermore, devolo dLAN devices are compatible to the HomePlug standard, i.e. they operate with all other devices being compatible to this standard. Question: Do I have to modify the power supply to install the dLAN adapters? Do I encounter 230 volt? Answer: No, you don't have to modify anything on your power supply lines. And you do not encounter 230 volt. Question: Do I have to turn off the fuse to install the dLAN adapters? Answer: No, you don't have to.
Question: In my house are three separate phases. Can MicroLink dLAN Ethernet or MicroLink dLAN USB connect one phase to another? Answer: Yes,it can.Phase coupling operates without an installation of a phase coupler using dLAN adapters. You also can establish your network connections via two or three phases. Question: I'm living in a very old house with old power supply lines (partly without separated ground wire). Does dLAN operate nevertheless? Answer: dLAN will also operate correctly in this case. Question: Can my neighbour listen to my data when he is connected with the same power supply? Answer: Your electric meter damps the signal enormously and represents a natural barrier to your neighbour. However, if you have unfavourably lying power supply lines it is possible that your neighbour benefits from an unmeant phase coupling. We absolutely advise you to use the internal device encryption! Entering a password which differs from the factory default will activate the encryption. Question: How safe are my data? Is it possible to tap them in some way? Answer: We absolutely advise you to use the internal device encryption! Entering a password which differs from the factory default will activate the encryption. Question: Do I have to plug the devolo MicroLink dLAN adapter directly in the wall socket or can I also plug it into an extension or into a multiple socket (partly with switch)? Answer: Short answer: You can. Both.
Question: My computer has a crowbar circuit. Do I have to plug in the dLAN adapter before or behind the crowbar circuit? Answer: Please plug in the dLAN adapter before the crowbar circuit. For technical reasons, a dLAN adapter cannot be used with an additional crowbar circuit. Even it operates, you will lose performance and stability. Question: Which devices do I need for the initial installation of a dLAN network? Answer: You always need two adapters for the initial installation, regardless if Ethernet (MicroLink dLAN Ethernet) or USB (MicroLink dLAN USB). If you want to connect your network to the Internet, you need at least one adapter with Ethernet interface (MicroLink dLAN Ethernet). This adapter is to be connected to an ADSL modem (only one participant of the network can use the Internet) or to an ADSL modem router (all participants of the network can use the Internet at the same time). Question: Are dLAN devices compatible to other LAN products? Answer: You can combine devolo MicroLink dLAN products with all other devolo LAN products or with all devices which are conform to the IEEE 802.3 standard. Question: Do I have to worry about an electric shock by the Ethernet? Answer: No, you don't have to. The two electric circuits are separated from each other. Question: Do dLAN adapters interfere other domestic appliances? Answer: No, they don't. dLAN products are certified according to all essential standards, also the testing according to emission and interference.
Question: Do other domestic appliances interfere dLAN devices in their operation mode? Answer: All devices which are sold within the EU have to be labeled with the CE emblem. This guarantees that the devices don't interfere each other. Question: On which frequences does dLAN operate? Does this technology interfere the reception of radio or amateur radio? Answer: Typically today radio reception take place on UKW in the range of 87,20 to 108,00 MHz. The frequences used by dLAN-technology are in the range of 4MHz to 21MHz and so they cannot interfere your UKW radio. The technology is based on the HomePlug standard, in which the transmitting level is specially lowered in the amateur radio band. The used transmitting level is very small and by the symmetrical coupling, only a small part of this power will be radiated by the power grid. Consequently in the amateur band are none interferences awaited. Question: Does dLAN deal with Powerline Internet? Answer: No, the Powerline communication supplied your house with Internet via powerline. With Powerline longer distances had to be covered which could only be realized with higher signal levels. The HomePlug standard addresses to indoor data communication and uses only very small signal levels. Question: Is there a risk that electromagnetic interferences distribute all-over in the house using dLAN adapters? Or even to the neighbours? Answer: dLAN devices are tested according to the same norms like other electric devices (EN55022), the devices generate the same noise level than other electrical equipment. So that, dLAN devices don't produce more interference than a power drill, e.g.. Question: Can dLAN products operate all over Germany or are they firstly restricted to a specified region? Answer: Yes, the MicroLink dLAN product line can be used all over Germany where a standard electric installation is available.
Question: Are dLAN products already available in trade? Answer: The MicroLink dLAN products are already available in trade since April 2003. Sources of supply can be found at the devolo homepage: www.devolo.com. Question: Do any costs arise for a modulation of additional frequencies? Answer: No, the only costs arises by purchasing the necessary number of MicroLink dLAN adapters. This technology is not the technology "PowerLine" realizing an Internet access via power socket. MicroLink dLAN devices only enable the connection of several computers to an indoor network — without installing additional cables. These devices comply with the so-called HomePlug standard. However, due to the connection of an modem router to a power socket, it is possible that your network computers reach the Internet. Question: Is it possible to simply modulate additional frequencies on the power lines or is there something to consider on the part of the energy provider? Can the provider collect charges? Answer: It's easy. The provider does nothing and can't collect any charges. Question: Do I need a particular provider for Internet access or a specified dial-up procedure? Or can I keep up my present dial-up mode? Answer: The Internet dial-up is absolutely independent of using MicroLink dLAN devices. You also can network your computers via the MicroLink dLAN products without Internet access. If you want that your network reaches the Internet you will need a router. At our home page under the following address http://www.devolo.info/downloads/faxsheet/faxsheet_devolo_microlink_dlan_de.pdf you will find application examples.
Question: Are the data transmission rates as high as the rates of the conventional DSL connection? Answer: The bandwidth of MicroLink dLAN products depends on the interferences on your power cabling and of the quality of the electrical installation. It ranges from 5 MBit to 14 MBit (a conventional DSL connection has 0.768 MBit download and 0.128 MBit upload rate). This is quite sufficient for extending the DSL connection to all rooms in the house. Question: The power supply operates with 50Hz. Is it possible to achieve reasonable ping times in the range of milliseconds? Answer: dLAN doesn't operate with a 50Hz alternating frequency. dLAN operates in the range of MHz. Therefore, ping times in the range of msec are possible. Question: How many dLAN adapters can operate within an one-family house? Answer: 253 connections are theoretically possible. But in practice, no more than ten devices should transfer data at the same time. Question: If one dLAN adapter is connected to a MicroLink LAN Switch, is it possible that all other computers connected to the switch can communicate with all other dLAN members? Answer: Yes, of course, you can. Question: How can I prevent (e.g. in a flat-sharing community) that someone buys a dLAN adapter and listens to the data transmitted between my dLAN adapters? Answer: By using the internal device encryption which will be activated by the enclosed software.
Question: Can I combine some dLAN adapters to a private group and save them by a common password? Answer: Yes, of course, this is possible. Question: Does a configuration software exist configuring dLAN adapters in common? Answer: Yes, such a software exists. Question: How does the HomePlug technology differ from the Internet Powerline technology? Why did Internet Powerline not become accepted in the market when HomePlug is functioning? Is it another technology? Answer: There are two important differences between the technologies HomePlug and Internet Powerline. On the one hand, with HomePlug the distancies which must be covered are smaller. Therefore, Internet Powerline had to transmit with stronger signal levels. This caused different problems, e.g. problems concerning radiation and compatibility to other devices (electromagnetic compatibility CE/EMC). Furthermore, with Internet Powerline the provided bandwidth had to be shared with up to several hundred members and with Homeplug, the bandwidth is only shared among some users. Question: On which level do the dLAN adapters transmit? Answer: The transmitting power spectrum is -50dBm/Hz, on amateur radio frequences 80dbm/Hz, with a bandwidth of about 17MHz is that about +22dBm (160mW) or about -8dBm (160uW) (all values based on 50 Ohm.) As the coupling is symmetrical, only a small part of this performance is radiated.
Question: How much is the power consumption (in watt)of both dLAN adapters from 230 volt power supply? Answer: The power consumption of dLAN USB is 0 watt at the 230 volt power supply system and 1.25 watt at the USB port. The MicroLink dLAN Ethernet has a power consumption of 3 watt at the power supply system. Question: How safe is the 56Bit encryption? Answer: To decrypt the data you have to attain to the encrypted row data. But this fact will be prevented due to the HomePlug compatible hardware. The chip does not directly forward encrypted data to the host interface. Only each key in the chip can be decrypted. Due to the diversity of keys and a transmission rate between computer and chip of 100 Mbps it would take about 45000 ages. Question: Are the dLAN adapters compatible to Linux and Mac? Are they applicable on any other operating system, too? Answer: dLAN Ethernet is applicable with all TCP/IP operating systems. Drivers are not required for this adapter. But the supplied configuration software to assign the password, operates only with Windows operating systems. There is no problem to configure a dLAN Ethernet on a Windows computer and then, to use it on a TCP/IP operating system like Mac or Linux. Regarding to the dLAN USB adapter drivers for Windows 98, ME, 2000 and XP USB are supplied e. g. this adapter only works with these operating systems.
Question: I got the impression, that the transmission rates, which are indicated by the MicroLink Informer, are uncommon low. Which values are in the realm of normality? What can I do to boost the transmission rates? Answer: Under normal circumstances, transmission rates of 5-8 mbit/s are not uncommon. Please remember that the transmission rate falls with increasing reach (max. 200 m) and number of adapters (reasonable not more than 10-15). To increase the data rate you should attend to plug in the dLAN adapters directly into the wall socket. Don’t use unnecessary extension cable and multiple sockets. If this cannot be avoided, please attend, that the multiple socket doesn’t have any crowbar circuit. This could impair or even inhibit the data transmission. Plug in as few as possible devices in the multiple socket. If the data transmission proceeds on one phase instead of two phases beyond, you can expect increased reach and data rate. If it’s not possible to increase the data rates with these options, only the application of a phase coupler could be helpful (REGP phase coupler by Brennenstuhl available at: www.akkukompass.de). Question: How much is the transmitting power of a dLAN adapter compared to a handy or mobile home telephone? Answer:
SAR (specific absorption rate; unit: W/kg) is a physical item to measure the absorption of electromagnetic fields in biological material. This absorption causes a warming of the material. It strongly depends on the frequency and on the size of the absorbing item due to resonance effects.
As the size of the absorbing human is nearly constant the SAR is depending most on frequency. As shown in the diagram, the HomePlug technology of the MicroLink dLAN adapters is—compared to the technology of cellular phones and WLAN—in a frequency band 100-times lower and therefore causes a considerably lower SAR. Using the in-house power supply lines as transmission medium the HomePlug technology only emits very small parts of the signal. To limit the radiation of lines used by telecommunications institutions (also HomePlug), the RegTP lays down the provision 30 (NB 30) which came into effect at 1 July, 2001. It defines the use of frequencies between 9 kHz and 30 MHz (at 1 July, 2003 up to 3 GHz) within and along conductors as well as maximum disturbance level. The limit value of the disturbance levels which has to be measured with a required measurement setup at a distance of three meters, see the following diagram:
However, a look at the maximum allowable emitted disturbance (according to NB30) of HomePlug shows that these disturbance are very low—compared to the valid limits (according to ICNIRP recommandations) of "normal" transmitters in most of the countries. This diagram shows the maximum electrical field strength according to the CNIRP directives (in blue) and the maximum values according to the provision NB 30 (in green) applied for a distance of 3m. In comparison to the "Salzburger Vorsorgewert" of 1000 µW/m², the HomePlug maximum value in a distance of 1 cm nearly underlies with a factor of 4000. An electrical filed strength of 0.01 V/m complies with a power density of 0.26 µW/m². A DECT station (mobile home phone) produces a power density of 17500 µW/m² in a distance of 1.5 which exceeds the value of the HomePlug technology by 67000times. Even a GSM access point produces at a distance of 50 m a power density which is 60000-times higher than the power density of the MicroLink dLAN adapter. Therefore, the risk of biological or healthy effects by HomePlug or MicroLink dLAN can be classified as very low.
Question: In order to increase the distance of my dLAN-Network I am looking for a dLAN repeater. Does devolo offer such product? Answer: You can increase the distance, by combining two dLAN networks with two different dLAN passwords. The repeater is built up by two standard dLAN Ethernet adapters, which you simply connect via an Ethernet RJ45 cable. Please note that physically you are still using one medium, this means the bandwith will be shared between both networks. You can repeat this procedure several times.
