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工业路由器NBMA网络转化为点到点的链路 当我们使用点到点子接口将NBMA网络转化为点到点的链路时,整个NBMA网络将产生过多的PVC部分互联或全互联的网状结构,但这将产生一定的负面影响,会使网络中产生大量的LSP泛洪流量。我们都知道,运行IS-IS的工业路由器当接收到一个LSP报文后,会将此LSP从除接收接口以外的所有启用了IS-IS协议的接口泛洪出去,以使网络中的其他工业路由器都可以接收到此LSP。但是这种泛洪机制对于存在大量部分互联或全互联的网络将产生过多冗余的LSP扩散。 所谓全互联或全网状网络拓扑,是指所有工业路由器都与其他工业级无线路由器向连接(通常是点到点子接口)。在这样的一个网络中,当一台路由器从某接口收到邻居泛洪过来的LSP后,由于它并不知道这个LSP是否已经被其他邻居工业4g路由器收到,所以会再从其他接口泛洪出去,即使其他工业级4g路由器的链路状态数据库中已经存在这个LSP。如果网络中有n个全网路由器的话,那么网络中的每台工业级LTE路由器都会扩散n-2条冗余的LSP,这样总共被泛洪的多余的LSP将为(n-1)x(n-2),条而这些LSP的扩散是多余。如果每台工业全网通路由器都刷新一条LSP的话,那么这个数量还将会成倍数的增长,导致了大量带宽资源的浪费。 为了解这种在全互联或高度互联的网络中出现的LSP泛洪的冗余现象,IS-IS提供了一种解决方案——IS-IS全通组,也称作Mesh组。IS-IS全通组在RFC2973中进行了定义。所谓全通组,就是假设所有工业3G路由器之间都是完全互联的,每个工业级全网通路由器都会直接收到其他全网通工业级路由器泛洪的原始的LSP的拷贝。 可以将全网工业路由器的接口加入到某个全通组中,一个全网通工业路由器上可以存在多个全通组,全通组内接口之间的LSP泛洪是受限制的,全通组之间的LSP泛洪是正常的操作,未加入全通组的工业级3G路由器接口与全通组之间也是正常的LSP泛洪操作。全网通路由器 ...

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工业路由器使用CSNP来保证链路状态数据库的完整性 在广播网络中,工业路由器使用CSNP来保证链路状态数据库的完整性,并且只有DIS才会发送工业全网通路由器CSNP报文,DIS发送CSNP报文的间隔为10s。CSNP报文中描述了DIS的链路状态数据库中所有工业级3G路由器LSP的摘要信息。当其他工业级路由器收到DIS发送的CSNP后,会使用CSNP中的LSP摘要信息与与本地的链路状态数据库中的LSP进行比较,进行比较的目的是确定本地链路状态数据库中的信息是否已经同步和完整。如果工业级4g路由器发现本地数据库中缺少某个LSP条目,那么它将使用PSNP向DIS请求这个缺少的LSP条目。这个PSNP报文中包含就是请求的LSP条目的摘要信息。当DIS收到其他全网路由器发送的PSNP报文后,将会发送一个完整的LSP报文,这个LSP就是其他工业无线路由器所缺少的LSP条目。在广播网络中,DIS使用周期性的CSNP报文向网络中发送同步链路状态数据库的信号,而其他工业4g路由器使用PSNP报文来请求缺少的LSP条目。 在IS-IS的点到点类型的网络中,链路状态数据库同步的操作与广播网络中略有不同,而且工业级全网通路由器发送CSNP与PSNP报文的方式和其作用也有一些差别。 在点到点网络中不存在DIS,工业3G路由器不会周期性的发送CSNP报文,CSNP报文只在链路链路被激活时发送一次,而且链路两端的工业级4g路由器都会发送CSNP报文以描述本地链路状态数据库中所有LSP的摘要信息。当工业路由器发送对端发送的CSNP中含有本地缺少的LSP信息时,也会使用PSNP报文向对端请求LSP。当对端收到PSNP报文后,将向请求方发送包含完整LSP信息的LSP报文,这点上与广播网络中的操作是相同的。但是在点到点链路上,收到LSP报文的工业4g路由器还会向对方再次发送一个PSNP报文以对之前收到的LSP进行确认。可以说,在点到点网络中的LSP交换是可靠的。这点与广播网络不同,在广播网络中工业级无线路由器不使用PSNP报文对收到的LSP进行确认,而是通过DIS周期性地发送CSNP报文以弥补广播网络中不可靠的LSP交换。 在点到点链路上,工业路由器使用PSNP对收到的LSP报文进行确认,所以在点到点链路上是可靠的泛洪机制。 IS-IS路由协议支持两种网络类型:广播链路和点到点链路。默认情况下,全网通工业级路由器IS-IS将广播网络和NBMA网络看作是广播类型。对于封装了PPP或HDCL等协议的链路看作是点到点类型。对于NBMA网络中的主接口和点到多点子接口,IS-IS将其看作是广播类型;对于NBMA网络中的点到点子接口,将其看作是点到点类型。IS-IS不像OSPF那样,提供了对NBMA网络(例如Frame-Relay、ATM)的专门支持。对于NBMA网络,全网通工业路由器IS-IS认为其网络拓扑是PVC全互联(mesh)的,就是把它看作广播网络。但如果实际网络拓扑中并不是PVC全互联的结构时,例如部分互联的结构和Hub-Spoke结构,推荐使用点到点类型网络,即使用点到点子接口,以免造成NBMA网络中的链路状态数据库同步出现问题。无线路由器

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工业级路由器LSP校验和(Checksum) 当工业路由器生成一个LSP后,为了保证LSP中信息的完整性,它将对LSP进行校验和计算,然后封装进LSP的LSP校验和字段(checksum)。校验和的计算包括从LSP中的剩余时间字段之后的字段一直到数据包的末尾,由于剩余时间是一个不断变化的字段,所以校验和计算将不包括这部分内容。校验和主要用于检查被破坏的LSP或者还没有从网络中清除的过期LSP。当一台工业4g路由器收到一个LSP,在将该LSP放入到本地链路数据库和将其再泛洪给其他邻接工业3G路由器之前,会重新计算LSP的校验和,如果校验和与LSP中携带的校验和不一致,则说明此全网通工业级路由器LSP传输过程中已经被破坏。 当工业路由器收到了一个被破坏的LSP后,会采取一个清除的操作。它将该LSP的剩余时间设置为0然后再泛洪到网络中。当网络中的其他工业LTE路由器收到这个剩余时间被置为0的LSP后,会将其本地链路状态数据库中相应的LSP清除。当产生这个被破坏的LSP的源双卡路由器收到这个剩余时间被置为0的LSP并发现这个LSP是自己生成的后,会重新生成一个正确的LSP然后泛洪到网络中。 IS-IS的这种LSP清除操作虽然可以有效的清除网络中被破坏的LSP,给运行工业级4G路由器IS-IS路由协议的网络提供了一种自动修复的能力,但是它也带来了一种负面的影响。如果网络中的介质存在问题,就有可能产生LSP被连续破坏的现象。这些被破坏的LSP会被路由器不断的清除,同时源工业无线路由器也会不断的重新生成新的LSP,这种现象被称为LSP破坏风暴。LSP破坏风暴将消耗大量的网络资源。我们可以对工业级无线路由器进行配置,使其在收到被破坏的LSP后忽略它,即丢弃被破坏的LSP,从而启动清除操作。在后续工业级全网通路由器IS-IS配置章节中将介绍具体的配置方法。 标签:4g路由器...

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伊林思:中间系统类型工业4G路由器(ISType) 在LSP报头中最后一个字节的中间系统类型(ISType)位占2bit,工业4G路由器的类型。该字段表示了此LSP是来自L1工业路由器还是L2工业级路由器。这也表示了收到此LSP的工业路由器将把这个LSP放到L1链路状态数据库还是L2链路状态数据库。该2bit中01表示L1;11表示L2;00与10未使用。 DIS和伪节点【4g路由器】 LSPID中包括一部分称为伪节点标识符(PseudonodeID),用来标识此LSP是否是由网络中的指定中间系统(DIS,DesignatedIntermediateSystem)为网络产生的伪节点LSP。 在广播类型的网络(LAN)中,IS-IS需要为每个网段选择一个指定中间系统DIS,这里的指定中间系统DIS的作用与OSPF中的指定工业级路由器DR的非常相似。在OSPF网络中,DR用来负责将链路状态信息泛洪到每个非DR工业路由器,并且帮助其进行链路状态数据库的同步。在IS-IS中也是如此,为了使链路状态信息更加准确和实时的同步给网络中的所有全网路由器,并且要减小带宽的利用率和路由器的处理开销,IS-IS也要在广播网络中选举出一个工业级无线路由器(DIS)来达到这个目的。 在IS-IS中选举DIS的过程也是非常简单的。每个运行IS-IS协议的全网通路由器的接口都拥有一个优先级(Priority),默认的优先级为64,同样也可以通过命令手工修改默认的优先级。工业4g路由器之间发送的HelloPDU中将携带接口的优先级信息。每个工业LTE路由器收到网络中其他工业级LTE路由器发送的HelloPDU后,通过比较优先级来进行DIS的选举。优先级数值越大的工业全网路由器将被选举为此网段的DIS。这里与OSPF不同的是,在OSPF中,如果接口的优先级为0,那么这台工业级全网通路由器将被认为没有资格成为此网段的DR。在IS-IS中,如果接口的优先级为0,这仅仅表示最低的优先级,但是此工业级4G路由器还拥有成为DIS的资格。当两台工业全网通路由器的接口优先级相同时,那么拥有更大的SNPA(在LAN中通常为MAC地址)的接口的工业级全网通路由器将成为DIS。在OSPF中如果优先级相同将比较RouterID。 在OSPF中,选举完DR后,还将选举出一个备份DR,BDR(BackupDR),以用来在原先DR出现故障时接替新的DR角色,并重新选举出BDR。但在IS-IS中,将不进行备份DIS的选举。如果DIS出现故障了,其他全网通工业路由器将会重新选举出一个DIS。其次,在OSPF中,DR和BDR的选举是非抢占模式的,也就是说当有更优优先级的路由器加入到现有网络中后,也不会抢占原先DR和BDR的角色。从某种意义上来讲,在OSPF网络中,第一台启动的双卡路由器将成为网络的DR,第二台启动的双路路由器将将成为BDR。与OSPF相比,DIS的选举是抢占的,即当有更优DIS资格双路路由器加入网络后,它会成为网络中新的DIS。这样,每次DIS的变更必须泛洪一组新的LSP。 默认情况下,运行IS-IS的双卡路由器将以每10s的间隔发送HelloPDU。但是对于一个DIS来说,由于它在网络中起到重要的作用,所以它发送HelloPDU的间隔的频率将是其他路由器的3倍,也就是说DIS以每3.3s的间隔发送HelloPDU。这样其他全网通工业路由器可以迅速检测出DIS出现故障并开始新的选举过程,增加了网络的收敛速度。无线路由器

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用于工业路由器指定策略的路由映射 Route Redistribution redistribute routing-process process-id [tag|metric|metic-type|subnets|route-map] *routing-process:BGP EGP Connected EIGRP IGRP ISIS ISO-IGRP Mobile ODR OSPF RIP and Static *ospf-metric:BGP缺省重分布度量 1 其他协议为20 *tag-value:附加到重分布工业路由器路由的一个32位的值,OSPF没有使用工业级无线路由器路由标记, 可以在用于指定策略的路由映射中引用,缺省标记为0 利用route-map控制重分布,并修改metric值,并做标记 如上图,基于标签来控制工业级路由器路由的重分布 Controlling...

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H820 Switch MC7710 from DIP to QMI to increase 4G LTE Data Speed

Category : 产品文章, 伊林思产品FAQ, 技术相关

Steps for updating,
1) open H820 case, take out the MC7710 radio module
2) install the MC7710 radio module into the M300 debug board with USB cable.
3) get one PC (called PC1), install MC7710-DIP windows drivers. Download drivers and GUI tool at link http://www.e-lins.com/EN/download/driver/MC7710-DIP.zip

4) get another PC(called PC2), install MC7710-QMI windows drivers. Download drivers and GUI tool at link http://www.e-lins.com/EN/download/driver/QMI_B3449_Watcher.zip   and  http://www.e-lins.com/EN/download/driver/QMI_Driver_B3574.zip

5) Download DIP-QMI switching tool at link http://www.e-lins.com/EN/download/driver/BZ31018_DIP_QMI_ModeSwitch.zip
Unzip it and put in PC1.

6) Put the SIM card into the M300 debug board. Connect M300 debug board with MC7710 radio module to PC1, power on the M300 debug board, the PC1 will find the device and finishing installing the drivers.
Run the sierrawireless GUI tool, check if can get signal and network.
Run the DIP-QMI switching tool “BZ31018_DIP_QMI_ModeSwitch.exe”, try to switch from DIP to QMI mode. Please do not touch the M300 board until the switching is finished.

7) Connect the M300 board with MC7710 radio module to PC2, power on the M300 debug board, the PC2 will find the device and finishing installing the drivers.
Run the sierrawireless GUI tool, check if can get signal and network.

8) Put the MC7710 radio back to H685 router.  Install the connectors and cables well.

9) Download newest firmware at link http://www.e-lins.com/EN/download/firmware/ H820_8M64M_V2.3.52_20130801
And update the H820 with this firmware.

10) At H820 router, please at WAN configuration page, select “AUTO” at “Cell Modem”. Do not forget to click “Apply” button. Then the router will search the radio module, and working with QMI mode, which can reach much faster speed than before.

 

What is VPN

Category : 其他, 技术相关

A virtual private network (VPN) extends a private network across a public network or internet. It enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network.

VPNs can provide functionality, security and/or network management benefits to the user. But they can also lead to new issues, and some VPN services, especially “free” ones, can actually violate their users’ privacy by logging their usage and making it available without their consent, or make money by selling the user’s bandwidth to other users.

Some VPNs allow employees to securely access a corporate intranet while located outside the office. Some can securely connect geographically separated offices of an organization, creating one cohesive network. Individual Internet users can use some VPNs to secure their wireless transactions, to circumvent geo-restrictions and censorship, and/or to connect to proxy servers for the purpose of protecting personal identity and location. But some Internet sites block access via known VPNs to prevent the circumvention of their geo-restrictions.

A VPN is created by establishing a virtual point-to-point connection through the use of dedicated connections, virtual tunneling protocols, or traffic encryption. A VPN available from the public Internet can provide some of the benefits of a wide area network (WAN). From a user perspective, the resources available within the private network can be accessed remotely.

Traditional

VPNs are characterized by a point-to-point topology, and they do not tend to support or connect broadcast domains, so services such as Microsoft NetBIOS may not be fully supported or work as they would on a local area network (LAN). Designers have developed VPN variants, such as Virtual Private LAN Service (VPLS), and layer-2 tunneling protocols, to overcome this

limitation.

Talking about Long Distance Wi-Fi

Category : 其他, 技术相关

Introduction
Since the development of the IEEE 802.11 radio standard (marketed under the Wi-Fi brand name), the technology has become markedly less expensive and achieved higher bit rates. Long range Wi-Fi especially in the 2.4 GHz band (as the shorter range higher bit rate 5.8 GHz bands become popular alternatives to wired LAN connections) have proliferated with specialist devices. While Wi-Fi hotspots are ubiquitous in urban areas, some rural areas use more powerful longer range transceivers as alternatives to cell (GSM, CDMA) or fixed wireless (Motorola Canopy and other 900 MHz) applications. The main drawbacks of 2.4 GHz vs. these lower-frequency options are:

poor signal penetration – 2.4 GHz connections are effectively limited to line of sight or soft obstacles
far less range – GSM or CDMA cell phones can connect reliably at > 16 km (9.9 mi) distances. The range of GSM, imposed by the parameters of Time division multiple access, is set at 35 km.
few service providers commercially support long distance Wi-Fi connections
Despite a lack of commercial service providers, applications for long range Wi-Fi have cropped up around the world. It has also been used in experimental trials in the developing world to link communities separated by difficult geography with few or no other connectivity options. Some benefits of using long range Wi-Fi for these applications include:

unlicensed spectrum – avoiding negotiations with incumbent telecom providers, governments or others
smaller, simpler, cheaper antennas – 2.4 GHz antennas are less than half the size of comparable strength 900 MHz antennas and require less lightning protection
availability of proven free software like OpenWrt, DD-WRT, Tomato that works even on old routers (WRT54G for instance) and makes modes like WDS, OLSR, etc., available to anyone. Including revenue sharing models for hotspots.
Nonprofit organizations operating widespread installations, such as forest services, also make extensive use of long-range Wi-Fi to augment or replace older communications technologies such as shortwave or microwave transceivers in licensed bands.

Applications
Business
Provide coverage to a large office or business complex or campus.
Establish point-to-point link between large skyscrapers or other office buildings.
Bring Internet to remote construction sites or research labs.
Simplify networking technologies by coalescing around a small number of Internet related widely used technologies, limiting or eliminating legacy technologies such as shortwave radio so these can be dedicated to uses where they actually are needed.
Bring Internet to a home if regular cable/DSL cannot be hooked up at the location.
Bring Internet to a vacation home or cottage on a remote mountain or on a lake.
Bring Internet to a yacht or large seafaring vessel.
Share a neighborhood Wi-Fi network.
Nonprofit and Government
Connect widespread physical guard posts, e.g. for foresters, that guard a physical area, without any new wiring
In tourist regions, fill in cell dead zones with Wi-Fi coverage, and ensure connectivity for local tourist trade operators
Reduce costs of dedicated network infrastructure and improve security by applying modern encryption and authentication.
Military
Connect critical opinion leaders, infrastructure such as schools and police stations, in a network local authorities can maintain
Build resilient infrastructure with cheaper equipment that an impoverished war-torn region can afford, i.e. using commercial grade, rather than military-class network technology, which may then be left with the developed-world military
Reduce costs and simplify/protect supply chains by using cheaper simpler equipment that draws less fuel and battery power; In general these are high priorities for commercial technologies like Wi-Fi especially as they are used in mobile devices.
Scientific research
See also: Wireless sensor network
A long range seismic sensor network was used during the Andean Seismic Project in Peru. A multi-hop span with a total length of 320 kilometres was crossed with some segments around 30 to 50 kilometers. The goal was to connect to outlying stations to UCLA in order to receive seismic data in real time.
Large-scale deployments
The Technology and Infrastructure for Emerging Regions (TIER) project at University of California at Berkeley in collaboration with Intel, uses a modified Wi-Fi setup to create long-distance point-to-point links for several of its projects in the developing world. This technique, dubbed Wi-Fi over Long Distance (WiLD), is used to connect the Aravind Eye Hospital with several outlying clinics in Tamil Nadu state, India. Distances range from five to over fifteen kilometres (3–10 miles) with stations placed in line of sight of each other. These links allow specialists at the hospital to communicate with nurses and patients at the clinics through video conferencing. If the patient needs further examination or care, a hospital appointment can then be scheduled. Another network in Ghana links the University of Ghana, Legon campus to its remote campuses at the Korle bu Medical School and the City campus; a further extension will feature links up to 80 km (50 mi) apart.

The Tegola project of the University of Edinburgh is developing new technologies to bring high-speed, affordable broadband to rural areas beyond the reach of fibre. A 5-link ring connects Knoydart, the N. shore of Loch Hourne, and a remote community at Kilbeg to backhaul from the Gaelic College on Skye. All links pass over tidal waters; they range in length from 2.5 km to 19 km.

Increasing range in other ways
Further information: 802.11 non-standard equipment and Radio propagation
Specialized Wi-Fi channels
For more details on this topic, see List of WLAN channels.
In most standard Wi-Fi routers, the three standards, a, b and g, are enough. But in long-range Wi-Fi, special technologies are used to get the most out of a Wi-Fi connection. The 802.11-2007 standard adds 10 MHz and 5 MHz OFDM modes to the 802.11a standard, and extend the time of cyclic prefix protection from 0.8 µs to 3.2 µs, quadrupling the multipath distortion protection. Some commonly available 802.11a/g chipsets support the OFDM ‘half-clocking’ and ‘quarter-clocking’ that is in the 2007 standard, and 4.9 GHz and 5.0 GHz products are available with 10 MHz and 5 MHz channel bandwidths. It is likely that some 802.11n D.20 chipsets will also support ‘half-clocking’ for use in 10 MHz channel bandwidths, and at double the range of the 802.11n standard.

802.11n and MIMO
Preliminary 802.11n working became available in many routers in 2008. This technology can use multiple antennas to target one or more sources to increase speed. This is known as MIMO, Multiple Input Multiple Output. In tests, the speed increase was said to only occur over short distances rather than the long range needed for most point to point setups. On the other hand, using dual antennas with orthogonal polarities along with a 2×2 MIMO chipset effectively enable two independent carrier signals to be sent and received along the same long distance path.

Power increase or receiver sensitivity boosting

A rooftop 1 watt Wi-Fi amp, feeding a simple vertical antenna on the left.
Another way of adding range uses a power amplifier. Commonly known as “range extender amplifiers” these small devices usually supply around ½ watt of power to the antenna. Such amplifiers may give more than five times the range to an existing network. Every 6 dB gain doubles range. The alternative techniques of selecting a more sensitive WLAN adapter and more directive antenna should also be considered.

Higher gain antennas and adapter placement
Specially shaped directional antennas can increase the range of a Wi-Fi transmission without a drastic increase in transmission power. High gain antenna may be of many designs, but all allow transmitting a narrow signal beam over greater distance than a non-directional antenna, often nulling out nearby interference sources. A popular low-cost home made approach increases WiFi ranges by just placing standard USB WLAN hardware at the focal point of modified parabolic cookware. Such “WokFi” techniques typically yield gains more than 10 dB over the bare system; enough for line of sight (LOS) ranges of several kilometers and improvements in marginal locations. Although often low power, cheap USB WLAN adapters suit site auditing and location of local signal “sweet spots”. As USB leads incur none of the losses normally associated with costly microwave coax and SMA fittings, just extending a USB adapter (or AP, etc.) up to a window, or away from shielding metal work and vegetation, may dramatically improve the link.

Protocol hacking
The standard IEEE 802.11 protocol implementations can be modified to make them more suitable for long distance, point-to-point usage, at the risk of breaking interoperability with other Wi-Fi devices and suffering interference from transmitters located near the antenna. These approaches are used by the TIER project.

In addition to power levels, it is also important to know how the 802.11 protocol acknowledges each received frame. If the acknowledgement is not received, the frame is re-transmitted. By default, the maximum distance between transmitter and receiver is 1.6 km (1 mi). On longer distances the delay will force retransmissions. On standard firmware for some professional equipment such as the Cisco Aironet 1200, this parameter can be tuned for optimal throughput. OpenWrt, DD-WRT and all derivatives of it also enable such tweaking. In general, open source software is vastly superior to commercial firmware for all purposes involving protocol hacking, as the philosophy is to expose all radio chipset capabilities and let the user modify them. This strategy has been especially effective with low end routers such as the WRT54G which had excellent hardware features the commercial firmware did not support. As of 2011, many vendors still supported only a subset of chipset features that open source firmware unlocked, and most vendors actively encourage the use of open source firmware for protocol hacking, in part to avoid the difficulty of trying to support commercial firmware users attempting this.

Packet fragmentation can also be used to improve throughput in noisy/congested conditions. Although packet fragmentation is often thought of as something bad, and does indeed add a large overhead, reducing throughput, it is sometimes necessary. For example, in a congested situation, ping times of 30 byte packets can be excellent, while ping times of 1450 byte packets can be very poor with high packet loss. Dividing the packet in half, by setting the fragmentation threshold to 750, can vastly improve the throughput. The fragmentation threshold should be a division of the MTU, typically 1500, so should be 750, 500, 375, etc. However, excessive fragmentation can make the problem worse, since the increased overhead will increase congestion.

Obstacles to long-range Wi-Fi
Methods that increase the range of a Wi-Fi connection may also make it fragile and volatile, due to various factors including:

Landscape interference
Obstacles are among the biggest problems when setting up a long-range Wi-Fi. Trees and forests attenuate the microwave signal, and hills make it difficult to establish line-of-sight propagation.

In a city, buildings will impact integrity, speed and connectivity. Steel frames and Sheet metal in walls or roofs may partially or fully reflect radio signals, causing signal loss or multipath problems. Concrete or plaster walls absorb microwave signals significantly, reducing the total signal.

Tidal fading
When point-to-point wireless connections cross tidal estuaries or archipelagos, multipath interference from reflections over tidal water can be considerably destructive. The Tegola project uses a slow frequency-hopping technique to mitigate tidal fading.

2.4 GHz interference
Main article: Electromagnetic interference at 2.4 GHz
Microwave ovens in residences dominate the 2.4 GHz band and will cause “meal time perturbations” of the noise floor. There are many other sources of interference that aggregate into a formidable obstacle to enabling long range use in occupied areas. Residential wireless phones, baby monitors, wireless cameras, remote car starters, and Bluetooth products are all capable of transmitting in the 2.4 GHz band.

Due to the intended nature of the 2.4 GHz band, there are many users of this band, with potentially dozens of devices per household. By its very nature, “long range” connotes an antenna system which can see many of these devices, which when added together produce a very high noise floor, whereby no single signal is usable, but nonetheless are still received. The aim of a long range system is to produce a system which over-powers these signals and/or uses directional antennas to prevent the receiver “seeing” these devices, thereby reducing the noise floor.

Dual SIM industrial router H750 Quick Start

Category : 产品文章, 伊林思产品FAQ, 技术相关

Before Installation and Configuration

  1. H750 router has different version. Study your router version before installation.
  2. For GSM/GPRS/EDGE/HSDPA/HSUPA/HSPA/HSPA+/4G LTE version, please get a SIM card with data business.
  3. For CDMA2000 EVDO/CDMA1x version, please get a UIM card with data business or inform us before order if the network uses non-ruim (nam-flashing).
  4. Make sure the sim card or uim card is with enough data business and balance.
  5. Make sure the signal is good enough where you test or install the router. Weak signal will make the router no work. If you find your signal strength is not good, please contact us for high gain antenna.

Notes: This quick start is for GSM/GPRS/EDGE/HSDPA/HSUPA/HSPA+/TD-SCDMA network only. For EVDO network or CDMA network, please refer to manual or contact us freely.

Step 1) Confirm the sim card if can work with other 2G/3G/4G router or modem. If the sim card can not work, the router will not work correctly.

Step 2) Connect the H750 Router LAN port to a PC via RJ45 cable. Make the PC automatically to get the IP, Submask, DNS.

The PC will get an IP of 192.168.8.xxx.

Step 3) At PC IE browser, please type: http://192.168.8.1

Username: admin      Password: admin

Step 4) Internet Settings – WAN – Cell Modem

Notes:

  • If you don’t replace any cellular module or not do the “Load Default to factory”, please skip this step and jump to Step 5.
  • Please be patient that the router will take some more time to dialup online for first configuration,

At “Cell Modem”, please select “AUTO_DETECT”, and click “Apply” button. The router will automatically detect the module modem.

Step 5) Set Cell SIM1

Setting location: H750 web “Internet Settings – WAN – APN configuration”

Click “Advance Parameter Groups” button, the H750 router will display the configuration page.

Fill in the related parameters. And DO NOT FORGET TO CLICK “Add/Edit” button.

Parameters Groups Name: you can fill in the name freely. But keep No Space between characters.

Dialup: fill in the related parameters. Get this parameter from the Sim Card Provider or Carrier;

APN: fill in the related parameters. Get this parameter from the Sim Card Provider or Carrier;

User: fill in the related parameters. Get this parameter from the Sim Card Provider or Carrier.
Notes: If your SIM card has no user name, please input out default value, otherwise the router may not dialup. Our default value for GSM/WCDMA/LTE is “wap”, and for CDMA/EVDO is “card”.

Password: fill in the related parameters. Get this parameter from the Sim Card Provider or Carrier.
Notes: If your SIM card has no user name, please input out default value, otherwise the router may not dialup. Our default value for GSM/WCDMA/LTE is “wap”, and for CDMA/EVDO is “card”.

 

Step 6) Set Cell SIM2. Follow Step 6 of setting Cell SIM1.

Step 7) Activate the “Cell SIM Switching Trigger” feature

Setting location: H750 web: Internet Settings – WAN — All Cell Option

There are 6 types of Cell Option Mode (Cell Switching Mode),

Mode Description
cell1 only With this mode, only sim1 works
cell2 only With this mode, only sim2 works
fail switch cell1 first With this mode, it works as below,
sim1 on – switch to sim2 on if sim1 failed, and keep working on sim2 – switch to sim1 on if sim2 failed, and keep working on sim1 –switch to sim2 on if sim1 failed, and keep working on sim2 – “cycling”
fail switch cell2 first With this mode, it works as below,
sim2 on – switch to sim1 on if sim2 failed, and keep working on sim1 – switch to sim2 on if sim1 failed, and keep working on sim2 –switch to sim1 on if sim2 failed, and keep working on sim1 – “cycling”
cell1 prefer With this mode, it works as below,
sim1 on – keep working on sim1 – if sim1 failed, switch to sim2 – keep working on sim2 for “Check Time (for Prefer mode)”, then try to check if sim1 is restored, if restored, switch to sim1 – “cycling”
cell2 prefer With this mode, it works as below,
sim2 on – keep working on sim2 – if sim1 failed, switch to sim1 – keep working on sim1 for “Check Time (for Prefer mode)”, then try to check if sim2 is restored, if restored, switch to sim2 – “cycling”
advance data traffic cell1 first With this mode, it works as below,
sim1 and sim2 have data limits. Sim1 on — once sim1 data count reaches the limitation, switch to sim2 — once sim2 data count reaches the limitation, sim1 and sim2 neither works until next day/week/month.With this mode, users need set the “Advance Cell Traffic” configuration
advance data traffic cell2 first With this mode, it works as below,
sim1 and sim2 have data limits. Sim2 on — once sim2 data count reaches the limitation, switch to sim1 — once sim1 data count reaches the limitation, sim1 and sim2 neither works until next day/week/month.With this mode, users need set the “Advance Cell Traffic” configuration. Refer to the detailed manuals from E-Lins.
cell on time traffic Sim1 and sim2 work according the time period schedule settings.

With this mode, users need set the “Advance Cell Traffic” configuration. Refer to the detailed manuals from E-Lins.

Notes: Sometimes it may happen the following,
1) Choosing ” fail switch cell1 first” or “cell1 prefer”, SIM2 is firstly online, this is not problem because sometimes the SIM1 has some problem to be online.

2) Choosing ” fail switch cell2 first” or “cell2 prefer”, SIM1 is firstly online, this is not problem because sometimes the SIM2 has some problem to be online.

Check Time (for Prefer mode): set the time for “cell1 prefer mode” or “cell2 prefer mode”

Description for Check Time (for Prefer mode):
For example1, Cell Option Mode is “cell1 prefer”, and Check Time (for Prefer mode) is “5” minutes. It works as below,
Router works with sim1 firstly — if sim1 failed, switch to sim2 — keep working on sim2 with 5 minutes — after 5 minutes, check if sim1 is ok, if ok, switch back to sim1.

For example2, Cell Option Mode is “cell2 prefer”, and Check Time (for Prefer mode) is “5” minutes. It works as below,
Router works with sim2 firstly — if sim2 failed, switch to sim1 — keep working on sim1 with 5 minutes — after 5 minutes, check if sim2 is ok, if ok, switch back to sim1.

Step 8) Click “View” button to double check if the settings are correct.

Step 9) Click “Apply” button or Re-power the router to reboot. Then H750 router will reboot and dialup online.

Once it’s online, the CELL LED will light on.
Notes: sometimes the router cannot dialup after the APN configuration, please power off the router, and re-power on it. Because some radio modules need reboot after the initial APN configuration.

Step 10) Once H750 router is online, it gets a WAN IP Address and Status Page will show similar info.

Step 11) Activate the “Cell ICMP Check” feature

Setting location: H750 web: Internet Settings – Cell ICMP Check

Notes:

1) For router working with best stability, we highly suggest activate and use this feature.

With this feature, the Router will automatically detect its working status and fix the problem.

2) Please disable the “Ping from WAN Filter” if use ICMP check feature, otherwise it cannot work.

 

  • Active: tick it to enable ICMP check feature
  • Check method: fill in checking domain name or IP. Click HOST/IP check button to verify before using it.
  • Check interval time (sec): set the interval time of every check
  • Check Count: set the checking count number
  • Reboot Count Before Sleep: H750 Router will sleep to stop checking after failed with set times.
  • Sleep Time (min): H750 Router sleep timing before resume check.

 

Example with above picture:

H750 Router check “www.google.com” and “112.134.8.8”, it will check 3 times. After the previous check, it will do next check after 60 seconds. Totally it will check 3 times. If 3 times all failed, H750 Router will reboot. If reboots 3 times continuously, H750 Router goes to sleep to stop checking. The sleep time is 5 minutes. After 5 minutes, H750 Router resumes to cycle the checking.

 

IoT Applications

Category : 其他, 技术相关

According to Gartner, Inc. (a technology research and advisory corporation), there will be nearly 20.8 billion devices on the Internet of things by 2020. ABI Research estimates that more than 30 billion devices will be wirelessly connected to the Internet of things by 2020. As per a 2014 survey and study done by Pew Research Internet Project, a large majority of the technology experts and engaged Internet users who responded—83 percent—agreed with the notion that the Internet/Cloud of Things, embedded and wearable computing (and the corresponding dynamic systems) will have widespread and beneficial effects by 2025. As such, it is clear that the IoT will consist of a very large number of devices being connected to the Internet. In an active move to accommodate new and emerging technological innovation, the UK Government, in their 2015 budget, allocated £40,000,000 towards research into the Internet of things. The former British Chancellor of the Exchequer George Osborne, posited that the Internet of things is the next stage of the information revolution and referenced the inter-connectivity of everything from urban transport to medical devices to household appliances.

Integration with the Internet implies that devices will use an IP address as a unique identifier. However, due to thelimited address space of IPv4 (which allows for 4.3 billion unique addresses), objects in the IoT will have to use IPv6to accommodate the extremely large address space required. Objects in the IoT will not only be devices with sensory capabilities, but also provide actuation capabilities (e.g., bulbs or locks controlled over the Internet). To a large extent, the future of the Internet of things will not be possible without the support of IPv6; and consequently the global adoption of IPv6 in the coming years will be critical for the successful development of the IoT in the future.

The ability to network embedded devices with limited CPU, memory and power resources means that IoT finds applications in nearly every field. Such systems could be in charge of collecting information in settings ranging from natural ecosystems to buildings and factories, thereby finding applications in fields of environmental sensing and urban planning.

On the other hand, IoT systems could also be responsible for performing actions, not just sensing things. Intelligent shopping systems, for example, could monitor specific users’ purchasing habits in a store by tracking their specific mobile phones. These users could then be provided with special offers on their favorite products, or even location of items that they need, which their fridge has automatically conveyed to the phone. Additional examples of sensing and actuating are reflected in applications that deal with heat, electricity and energy management, as well as cruise-assisting transportation systems. Other applications that the Internet of things can provide is enabling extended home security features and home automation. The concept of an “Internet of living things” has been proposed to describe networks of biological sensorsthat could use cloud-based analyses to allow users to study DNA or other molecules.

However, the application of the IoT is not only restricted to these areas. Other specialized use cases of the IoT may also exist. An overview of some of the most prominent application areas is provided here. Based on the application domain, IoT products can be classified broadly into five different categories: smart wearable, smart home, smart city, smart environment, and smart enterprise. The IoT products and solutions in each of these markets have different characteristics.

 

Differences between industrial class and SOHO class for Router / Modem

Category : 其他, 技术相关

As we know, the devices mainly cover three classes, that is SOHO class, Industrial class and Military class.  Each class has its own application requirement. The SOHO class modem and router don’t meet the requirements of the industrial environment and standard entirely because of it is designed for office automation. Mainly differences are the below,

1. Control
The SOHO class is simple design for internet use. People no need control it very often.
The industrial class is designed mainly for industry applications. People need control it quite often, even 7*24 hours.

2. Stable, reliable and robust
SOHO class features are simply. It is mainly used for internet surfing, which is installed in house. People can check and assist it in time. With cost requirement, SOHO class design and development will not care too much for the stability and reliability. The industrial class cares the stability and reliability very much because it’s mainly installed under people’ touch. In another world, it should be working for 7*24 hours without people assist. So the industrial class must have good reliability, recoverability, and maintainability in the production environment at the same time. It is a guarantee that it will not lead the collapse of applications, operating system even the network when any component failure occurs in a network system.

3. The security issues
Lots of fields exist inflammable, explosive or toxic gases inevitably in the process of industrial production, and there must have some certain explosion-proof technology for the intelligent devices and communication equipment which can ensure the safety of industrial field. It is much more practical to add explosion-proof and explosion-proof measures in the Ethernet system under the condition of current technology, namely the ignition energy which caused by the devices problem will not leak through increasing explosion-proof measures to the Ethernet field devices, which can ensure the safety of running system. For those dangerous situation where is no strict safety requirements, you can not consider complex explosion-proof measures.

The network safety of industrial system is another security issue must be considered at the industrial Ethernet applications. Industrial Ethernet can make the traditional three layers of the network system, namely, information management layer, process monitoring layer and field equipment layer, an organic whole, which make the faster data transfer, higher real-time and it can integrate with the Internet seamlessly, it realizes data sharing and improves the operational efficiency of the factory. But there is a series of network security problems at the same time, industrial network may under the threat of virus infection, hackers and illegal operation.

4. The vehicle power supply issues
The vehicle power supply refers to the cable connected to the field devices not only to transmit data signals, but also provide equipment working power supply on-site. The Ethernet hasn’t considered this issue from the design at the beginning, while there are a lot of bus power supply requirements on the industrial site. Because of the above problems, the ordinary commercial Ethernet cannot be applied to the control of industrial field directly. And the industrial Ethernet is produced to solve these problems.

 

5. Features and performance
The industrial class owns much more features and SOHO class, such as connection alive monitor and keeping, Dual Sim connection, multi-line redundancy, GPS, Serial ports, VPN networks, high gain and special antenna replacement, etc.

E-Lins 4G Wireless Router: Solutions for Transport

Category : 其他, 技术相关

Traffic Data Acquisition Application
Traffic Data Acquisition is among one important tasks in ITS. All the on-line or historical data are vital for the design and planning for the traffic management strategy. The traffic data acquisition device normal consists of two parts: the sensor and the controller. The controller links with the central through wire-line connection and send back the data collected from the sensor. However, installation of the wire-line relates to huge engineering efforts and the maintenance of fixed lines has always been difficult. There will be more problems to get wire-line connection in remote areas. When

the communication line goes down, data is lost unless a data Logger is further installed.

In this application, wireless module links with the Traffic Data Acquisition device using RS485 interface. The raw data from the detector is further analyzed by the data protocol analysis mechanism provided by the wireless module and sorted data is transmitted to the central Traffic Control Centre through GPRS network and Internet in TCP/IP packet. Data can be temporarily stored in the memory buffer when GPRS is disconnected. From the system integrator”s point of view, all the integration on the terminal wireless

connection is achieved by the plug & play of wireless module and no change is necessary on the original detecting device. And only simple application is required at the central to access the terminal data. The total system implementation is accomplished within 3 weeks.

High Gain Antenna–Yagi-Uda Antenna

Category : 产品文章, 伊林思产品FAQ, 其他

Today, we are talking about high gain antennas. Here I want to introduce a strong one. A Yagi–Uda antenna, commonly known as a Yagi antenna, is a directional antenna consisting of multiple parallel elements in a line, usually half-wave dipoles made of metal rods.

Yagi–Uda antennas consist of a single driven element connected to the transmitter or receiver with a transmission line, and additional “parasitic elements” which are not connected to the transmitter or receiver: a so-called reflector and one or more directors.

The Yagi–Uda antenna consists of a number of parallel thin rod elements in a line, usually half-wave long, typically supported on a perpendicular crossbar or “boom” along their centers. There is a single driven element driven in the center (consisting of two rods each connected to one side of the transmission line), and a variable number of parasitic elements, a single reflector on one side and optionally one or more directors on the other side. The parasitic elements are not electrically connected to the transmitter or receiver, and serve as passive radiators, reradiating the radio waves to modify the radiation pattern. Typical spacings between elements vary from about  110 to ¼ of a wavelength, depending on the specific design. The directors are slightly shorter than the driven element, while the reflector(s) are slightly longer. The radiation pattern is unidirectional, with the main lobe along the axis perpendicular to the elements in the plane of the elements, off the end with the directors.

It’s also a good choice for you when you use E-Lins routers in rural area. This antenna will gain better reception than standard antennas for routers.

E-Lins New Product H820q —— 5 Powerful Wifi Antenna Assembling

Category : 产品文章, 伊林思产品FAQ, 其他

Best way to assemble H820Q wifi antenna

WiFi1—to 5Ghz Main;

WiFi2–to 5Ghz Aux

WiFi3–to 5Ghz Aux2(for special wifi module)

 

WiFi4–to 2.4Ghz Main

WiFi5–to 2.4Ghz Aux

 

 

IoT WORLD FORUM 2017

Category : 产品文章, 伊林思产品FAQ, 其他

Conference information:

IoT WORLD FORUM 2017 will be held in London, November 15-16 – 2017

IoT WORLD FORUM, 2017 is the world’s leading Internet of Things Conference 2017 focusing on IoT applications, IoT Solutions and IoT Companies for all verticals including automotive, healthcare, asset and fleet management, manufacturing, security, retail point of sales, smart grid, smart metering, smart home and consumer electronics industry.

For more information, please visit the event site here: http://iotinternetofthingsconference.com