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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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A Brief Introduction of US largest Operator Verizon

Category : 其他, 技术相关

Verizon Communications, Inc. (simply known as Verizon), is a broadband telecommunications company and the largest U.S. wireless communications service provider as of September 2014, and a corporate component of the Dow Jones Industrial Average. The company is based at 1095 Avenue of the Americas in Midtown Manhattan, New York City, but is incorporated in Delaware.

 

What eventually became Verizon was founded as Bell Atlantic, which was one of the seven Baby Bells that were formed after AT&T Corporation was forced to relinquish its control of the Bell System by order of the Justice Department of the United States. Bell Atlantic came into existence in 1984 with a footprint from New Jersey to Virginia, with each area having a separate operating company (consisting of New Jersey Bell, Bell of Pennsylvania, Diamond State Telephone, and C&P Telephone).

 

As part of the rebranding that the Baby Bells took in the mid-1990s, all of the operating companies assumed the Bell Atlantic name. In 1997, Bell Atlantic expanded into New York and the New England states by merging with fellow Baby Bell NYNEX. In addition, Bell Atlantic moved their headquarters from Philadelphia into the old NYNEX headquarters and rebranded the entire company as Bell Atlantic.

 

In 2000, Bell Atlantic merged with GTE, which operated telecommunications companies across most of the rest of the country that was not already in Bell Atlantic’s footprint. Bell Atlantic, the surviving company, changed its name to “Verizon”, a portmanteau of veritas (Latin for “truth”) and horizon.

 

As of 2016, Verizon is one of three companies that had their roots in the former Baby Bells. The other two, like Verizon, exist as a result of mergers among fellow former Baby Bell members. One, SBC Communications, bought out its former parent AT&T Corporation and assumed the AT&T name. The other, CenturyLink, was formed initially in 2011 by the acquisition of Qwest (formerly named US West).

LTE CAT4/CAT6释义

Category : 其他, 技术相关

LTE CAT4/CAT6释义

  LTE CAT全名LTE UE-Category,拆开来解释, LTE指的是4G LTE网络、UE是指用户设备、Category翻译为等级。通顺解释就是用户设备能够支持的4G LTE网络传输速率的等级,也可以说成是4G网络速度的一个技术标准。所以LTE CAT4/CAT6就是指用户设备LTE网络接入能力等级为4或6。

  既然等级不同,那么其能力也肯定是不一样的,下面我们来看看LTE CAT4/CAT6影响了什么性能,分别是什么水平。简单来说,LTE CAT影响的就是4G LTE上行、下行网络速度的上限,通俗来讲就用户设备所能达到的上传、下载速度最大值。

r_4912859[1]

  在LTE CAT中不仅有4、6两个等级,上表是我们罗列的目前已知的LTE CAT等级以及对应的最大传输速度。其中LTE CAT4/CAT6也是目前4G手机的网络传输技术水平,而速度更快的CAT7和CAT8则仍处于实验室阶段,并未商用开发。

  

What is OpenWrt

Category : 其他, 技术相关

OpenWrt is an embedded operating system based on the Linux kernel, primarily used on embedded devices to route network traffic. The main components are the Linux kernel, util-linux, uClibc or musl, and BusyBox. All components have been optimized for size, to be small enough for fitting into the limited storage and memory available in home routers.
OpenWrt is configured using a command-line interface (ash shell), or a web interface (LuCI). There are about 3500 optional software packages available for installation via the opkg package management system.
OpenWrt can run on various types of devices, including CPE routers, residential gateways, smartphones, pocket computers (e.g. Ben NanoNote), and laptops. It is also possible to run OpenWrt on personal computers, which are most commonly based on the x86 architecture.
History
The project came into being because Linksys built the firmware for their WRT54G series of wireless routers from publicly available code licensed under the GPL. Under the terms of that license, Linksys was required to make the source code of its modified version available under the same license, which in turn enabled independent developers to create additional derivative versions. Support was originally limited to the WRT54G series, but has since been expanded to include many other chipsets, manufacturers and device types, including Plug Computers and Openmoko mobile phones.
Using this code as a base and later as a reference, developers created a Linux distribution that offers many features not previously found in consumer-level routers. Some features formerly required proprietary software. Before the introduction of OpenWrt 8.09, using Linux 2.6.25 and the b43 kernel module, WLAN for many Broadcom-based routers was only available through the proprietary wl.o module that was also provided for Linux kernel version 2.4.x only.
The code names of OpenWrt branches are named after alcoholic beverages, usually including their recipes in the MOTD as well, cf. White Russian, Kamikaze, Backfire, Attitude Adjustment, Barrier Breaker.
The bleeding edge development trunk was confusingly also called Kamikaze until February 2011 but with r25514 it was renamed as “Attitude Adjustment” and is now being constantly renamed to the next stable name.
Features
OpenWrt follows the bazaar-philosophy and is known for an abundance of options. Features include:
• A writable root file system, enabling users to add, remove or modify any file. This is accomplished by using overlayfs to overlay a read-only compressed SquashFS file system with a writable JFFS2 file system in a copy-on-write fashion. JFFS2 supports flash wear leveling.
• The package manager opkg, similar to dpkg, enables users to install and remove software. The package repository contains about 3500 packages. This contrasts with Linux-based firmwares based on read-only file systems without the possibility to modify the installed software without rebuilding and flashing a complete firmware image.
• A set of scripts called UCI (unified configuration interface) intended to unify and simplify the configuration of the entire system
• Extensible configuration of the entire hardware drivers, e.g. built-in network switches and their VLAN-capabilities, WNICs, DSL modems, FX, available hardware buttons, etc.
• Exhaustive possibilities to configure network-related features, like:
• IPv4 support.
• IPv6 native stack:
• Prefix Handling,
• Native IPv6 configuration (SLAAC, stateless DHCPv6, stateful DHCPv6, DHCPv6-PD),
• IPv6 transitioning technologies (6rd, 6to4, 6in4, ds-lite, lw4o6, map-e),
• Downstream IPv6 configuration (Router Advertisement, DHCPv6 (stateless and stateful) and DHCPv6-PD).
• Routing through iproute2, Quagga, BIRD, Babel etc.
• Mesh networking through B.A.T.M.A.N., OLSR and IEEE 802.11s-capabilities of the WNIC drivers
• Wireless functionality, e.g. make the device act as a wireless repeater, a wireless access point, a wireless bridge, a captive portal, or a combination of these with e.g. ChilliSpot, WiFiDog Captive Portal, etc.
• Wireless security: Packet injection, e.g. Airpwn, lorcon, e.a.
• Stateful firewall, NAT and port forwarding through netfilter; additionally PeerGuardian is available
• Dynamically-configured port forwarding protocols UPnP and NAT-PMP through upnpd, etc.
• Port knocking via knockd and knock
• TR-069 (CWMP) client
• IPS via Snort (software)
• Active queue management (AQM) through the network scheduler of the Linux kernel, with many available queuing disciplines. CoDel has been backported to Kernel 3.3. This encapsulates Traffic shaping to ensure fair distribution of bandwidth among multiple users and Quality of Service (QoS) for simultaneous use of applications such as VoIP, online gaming, and streaming media without experiencing the negative impacts of link saturation.
• Load balancing for use with multiple ISPs using source-specific routing
• IP tunneling (GRE, OpenVPN, pseudowire, etc.)
• Extensible realtime network monitoring and statistics through e.g. RRDtool, Collectd, Nagios, Munin lite, Zabbix, etc.
• Domain Name System (DNS) and DHCP through Dnsmasq, MaraDNS, etc.
• Dynamic DNS services to maintain a fixed domain name with an ISP that does not provide a static IP address
• Wireless distribution system (WDS) including WPA-PSK, WPA2-PSK, WPA-PSK/WPA2-PSK Mixed-Mode encryption modes
• OpenWrt supports any hardware that has Linux support; devices that can be connected (e.g. over USB) to an embedded device include
• Printers
• Mobile broadband modems
• Webcams
• Sound cards
• Notable software packages to use the hardware support are:
• File sharing via SAMBA, (Windows-compatible), NFS and FTP, printer sharing over the print server CUPS (spooling) or p910nd (non-spooling)
• PulseAudio, Music Player Daemon, Audio/Video streaming via DLNA/UPnP AV standards, iTunes (DAAP) server
• Asterisk (PBX)
• MQ Telemetry Transport through Mosquitto
• An extensive Ajax-enabled web interface, thanks to the LuCI project
• Regular bug fixes and updates, even for devices no longer supported by their manufacturers

 

Link to E-Lins OpenWrt Products:

http://www.e-lins.com/EN/download/H685_Datasheet_Eng.pdf

http://www.e-lins.com/EN/download/H820_Datasheet_Eng.pdf

http://www.e-lins.com/EN/download/H850_Datasheet_Eng.pdf

http://www.e-lins.com/EN/download/H860_Datasheet_Eng.pdf

E-Lins Frequently-used module parameters

Category : 伊林思产品FAQ, 技术相关

Supplier Module type Area Parameters
Ericsson F3307 UMTS/HSDPA/HSUPA: 2100/900MHz
GSM/GPRS/EDGE:1900/1800/900/850MHz;
Download Speed: 7.2Mbps;    Upload Speed: 5.76Mbps
Ericsson F3607gw UMTS/HSDPA/HSUPA: 2100/1900/850MHz
GSM/GPRS/EDGE:1900/1800/900/850MHz;
Download Speed: 7.2Mbps;    Upload Speed: 5.76Mbps
Ericsson F5521gw Global UMTS/HSDPA/HSUPA/HSPA+: 2100/1900/900/850MHz
GSM/GPRS/EDGE:1900/1800/900/850MHz;
Download Speed: 21Mbps;    Upload Speed: 5.76Mbps
Ericsson F5321gw Global UMTS/HSDPA/HSUPA/HSPA+: 2100/1900/900/850MHz
GSM/GPRS/EDGE:1900/1800/900/850MHz;
Download Speed: 21Mbps;    Upload Speed: 5.76Mbps
Huawei MU736 Global UMTS/HSDPA/HSUPA/HSPA+: 2100/1900/900/850MHz/AWS
GSM/GPRS/EDGE:1900/1800/900/850MHz;
Download Speed: 21Mbps;    Upload Speed: 5.76Mbps
Huawei MU709s-6 South America HSPA+/UMTS tri-band 850/1900/2100 MHz
GSM/GPRS quad-band 850/900/1800/1900 MHz
Huawei MU709s-2 Europe, Asia, Africa HSPA+/UMTS dual-band 900/2100 MHz
GSM/GPRS quad-band 850/900/1800/1900 MHz
Huawei MU609 HSPA+/UMTS quad-band 850/900/1900/2100 MHz
GSM/GPRS quad-band 850/900/1800/1900 MHz
Huawei ME909s-120 Most of Europe, Asia, Africa and South America LTE FDD: 2100/1900/1800/1700AWS/850/2600/900/800Mhz
(B1/B2/B3/B4/B5/B7/B8/B20)
3G: 850/900/1900/2100Mhz
2G: 850/900/1800/1900Mhz
Download Speed: 150Mbps;    Upload Speed: 50Mbps
Huawei ME909s-821 LTE FDD: 2100/1800/900Mhz  (B1/B3/B8)
LTE TDD: B38/B39/B40/B41
3G WCDMA: 2100/850/900/1700Mhz (B1/B5/B8/B9)
3G TD-SCDMA: B34/B39
2G GSM: 900/1800Mhz
Huawei ME909u-521 Most of Europe, Asia, Africa FDD LTE: 2600/2100/1900/1800/900/850/800Mhz (B1/B2/B3/B5/B7/B8/B20);
DC-HSPA+/HSPA+ /HSPA/UMTS: 850/900/1900/2100MHz(B1/B2/B5/B8),
EDGE/GPRS/GSM: 1900/1800/900/850MHz;
Download Speed: 100Mbps;    Upload Speed: 50Mbps
Huawei ME909u-523 US, South America LTE FDD: 1900/1700AWS/850/700Mhz(B2/B4/B5/B17)
DC-HSPA+/HSPA+ /HSPA/UMTS: 1900/1700AWS/850Mhz(B2/B4/5)
GSM: 850/900/1800/1900Mhz
Download Speed: 100Mbps;    Upload Speed: 50Mbps
Huawei ME906s-158 (M.2/NGFF) Europe, Asia and Oceania B28 LTE FDD:B1,B2,B3,B5,B7,B8,B20,B28
DC-HSPA+/HSPA+/HSPA/WCDMA:B1,B2,B5,B8
EDGE/ GPRS/GSM 1900/1800/900/850 MHz
Huawei ME906j (M.2/NGFF) Japan KDDI:
LTE: FDD Band 11, 18, all bands with diversity
CDMA 1X/CDMA EVDO Rev.B: BC0, BC6, all bands with diversity
GPS/GLONASS: L1
DOCOMO:
LTE: FDD Band 1, 19, 21, all bands with diversity
WCDMA/HSDPA/HSUPA/HSPA+: Band 1,5,6,19, all bands with diversity
GPS/GLONASS: L1
Huawei ME936 LTE (FDD) B1/B2/B3/B4/B5/B7/B8/B13/B17/B20
Penta-band DC-HSPA+/HSPA+/HSPA/UMTS B1/B2/B4/B5/B8
Quad-band EDGE/ GPRS/GSM 1900/1800/900/850 MHz
Sierrawireless MC7304 Most of Europe, Asia, Africa FDD LTE: B1/B3/B7/B8/B20  800/900/1800/2100/2600MHz(相对应为band 20/8/3/1/7)
WCDMA: 800/850/900/1900/2100 MHz(B6,B5,B8,B2,B1)
GSM 850/900/1800/1900MHz
Sierrawireless MC7354 US FDD LTE: 1900(B2), AWS(B4)
850(B5),700 (B13), 700(B17), 1900(B25)
UMTS/HSPA+: 2100(B1), 1900(B2), AWS(B4),850(B5),  900(B8)
CDMA EVDO/1x: BC0, BC1, BC10
Quad-Band EDGE/GPRS/GSM
Sierrawireless MC7350 US LTE: AWS(B4), 700(B13), 1900(B25)
CDMA 1x, EVDO Rev A:
BC0,BC1,BC10
Sierrawireless MC7330 Japan LTE: 2100 (B1), 850 (B19), 1500 (B21)
UMTS/HSPA+: 2100 (B1), 850 (B5) 800 (B6), 850 (B19)
Quad-Band EDGE/GPRS/ GSM
Sierrawireless MC7430 APAC FDD LTE:  B1, B3, B5-9,B18, B19, B21, B28                                                             TDD LTE:  B38,39,40,41                                                                                                    UMTS/HSPA+:2100(B1)  850(B5)/800(B6)/900(B8)/1800(B9)/850 (B19)
TD-SCDMA: B39(1900Mhz)
Sierrawireless ME3760 TDD LTE, LTE: 2600/2300/1900 (B38/B39/B40+B7);
TD-SCDMA: 2010~2025MHz/1880~1920MHz (B34/B39),
EDGE/GPRS/GSM: 1900/1800/900/850MHz;
Longsung U8301 Most of Europe, Asia, Africa FDD LTE: 2600/2100/1800/900/850MHz (B1/B3/B5/B7/B8)
DC-HSPA+/HSPA+ /HSPA/UMTS: 850/900/2100MHz (B1/B5/B8);
EDGE/GPRS/GSM: 1900/1800/900/850MHz;
Download Speed: 100Mbps;    Upload Speed: 50Mbps
Longsung U8300c TDD LTE: band38/39/40/41
FDD LTE: band1/3
TD-SCDMA: band34/39
UMTS: Band1
EVDO/CDMA1x: 800Mhz
GSM: 850/900/1800/1900Mhz
三旗 LM9206_ZAK Europe, Asia and Oceania B28 TDD LTE: band38/40
FDD LTE: band1/2/3/5/7/8/28
TD-SCDMA: none
UMTS: Band1/2/5/8
GSM: 850/900/1800/1900Mhz
三旗 LM9206_ZBK
(已经停产)
Most of Europe, Asia, Africa TDD LTE: band38/40
FDD LTE: band1/3/7/8/20
TD-SCDMA: none
UMTS: Band1/8
GSM: 850/900/1800/1900Mhz
Download Speed: 150Mbps;    Upload Speed: 50Mbps
三旗 LM9206_ZCK TDD LTE: none
FDD LTE: band1/2/5/7/8/28
TD-SCDMA: none
UMTS: Band1/5/8
GSM: 850/900/1800/1900Mhz
三旗 LM9206_ZDK Europe TDD LTE: band38/40
FDD LTE: band1/3/5/8
TD-SCDMA: none
UMTS: Band1/5/8
GSM: 850/900/1800/1900Mhz
三旗 LM9206_ZEK Europe, Asia TDD LTE: band38/39/40/41
FDD LTE: band1/2/3/5/7/8
TD-SCDMA: 34/39
UMTS: Band1/2/5/8
GSM: 850/900/1800/1900Mhz
三旗 LM9265 Europe, Asia TDD LTE: band38/39/40/41
FDD LTE: band1/3/5/7/8
TD-SCDMA: 34/39
UMTS: Band1/2/5/8
GSM: 850/900/1800/1900Mhz
CDMA/EVDO: BC0 800Mhz
ZTE ZM8620-A South America LTE TDD: band38
LTE FDD:2100/1900/1700 AWS/2600/850/900/700Mhz(B1/B2/B4/B5/B7/B8/B12)
DC-HSPA+/HSPA+ /HSPA/UMTS: 2100/1900/900/850/1700(AWS)Mhz
GSM: 850/900/1800/1900Mhz
Forge SLM630 TDD LTE: 2600/2300/1900 (B38/B39/B40/B41);
FDD LTE: 2100/1800/2600Mhz(B1/B3/B7);
DC-HSPA+/HSPA+ /HSPA/UMTS: 2100/1900/850Mhz (B1/B2/B5)
TD-SCDMA: 2010~2025MHz/1880~1920MHz (B34/B39),
EDGE/GPRS/GSM: 1900/1800/900/850MHz;
Download Speed: 100Mbps;    Upload Speed: 50Mbps
Forge SLM630b TDD LTE: 2600/2300/1900 (B38/B39/B40/B41);
FDD LTE: 2100/1800/2600Mhz(B1/B3/B7)
DC-HSPA+/HSPA+ /HSPA/UMTS: 2100/1900/850Mhz (B1/B2/B5)
TD-SCDMA: 2010~2025MHz/1880~1920MHz (B34/B39),
EDGE/GPRS/GSM: 1900/1800/900/850MHz;
EVDO/CDMA:BC0-800Mhz
Download Speed: 100Mbps;    Upload Speed: 50Mbps
LP41 FDD LTE, LTE: 450/800/1800/2600Mhz (B31/20/3/7)
Wetele WPD600N FDD LTE, LTE: 450/800/1800/2600Mhz (B31/20/3/7)

4G网络的语音解决方案

Category : 技术相关

4G商用已经有一段时间了。国内三家运营商各自使用的4G有些区别。 比如中国联通主要使用TDD LTE技术,而电信与联通主要使用FDD LTE技术。

目前4G主要有三种语音通话的解决方案:双待机、CSFB(Circuit Switched Fallback(电路域回落)和VoLTE(也及Voice over LTE)
1—-双待机:就是4G和3G/2G同时待机,4G用来上网,3G/2G则用来打电话,这种技术手机内部有两套射频发射系统,可想而知,这种技术,手机电池最多撑不到一天的,充电宝赚钱的机会是这样来的:)

2—-CSFB:就是通话时回落到2G模式(无法上网),通话结束后再恢复到4G/3G情况下,这种技术只使用一套射频芯片,现在我们4G测试主要是测试这种方案,毕竟4G网络还在建设中,有一些区域还没有完成覆盖到,这时切换很重要的。苹果用于电信的A1533的回落技术则另外取了一个名字叫做SRLTE,是一种特殊形式的CSFB。
—在国内,可以用DINGLI连三星和索爱的手机可以进行测试,有一些项目直接用IPHONE5S进行体验测试,在国外,主要用NEMO连三星,很少看到有用TEMS来测试!

3—-VoLTE:这种技术牛B呢,它是架构在4G网络上全IP条件下的端到端语音方案,接入时延大大提升,基本上没有掉话,以后肯定主要用这种技术了,毕竟2G时代快结束了,目前这种技术主要用于4G全覆盖的区域。
—测试软件方面,据说要用CHARIOT!

所以,严格的说,LTE网络只是数据网,在未实现VOLTE的情况下,LTE只能称之为3.5G,或是缺陷4G,只有包含了完美语音方案,不依赖2、3G网络的才能叫做4G网络。毕竟对于数据,语音还是很重要的。

SGLTE,SVLTE,SRLTE与CSFB的区别

Category : 技术相关

现在LTE已经广泛商用与三家运营商(中国移动,中国联通及中国电信)。 但是有些概念,我们需要分清下。比如SGLTE, SVLTE, CSFB及SRLTE。

SVLTE(Simultaneous Voice and LTE):即双待手机方式。手机同时工作在LTE和CS方式,前者提供数据业务,后者提供语音业务。

SGLTE (simultaneous GSM and LTE):LTE与GSM同步支持,终端包含了两个芯片。一个是支持LTE的多模芯片,一个是GSM的芯片。可以支持数据语音同时进行 。

SVLTE同SGLTE基本是一个概念,是一种单卡双待策略,手机插入一张卡,但可以同时工作在LTE网络和2/3G网络下(如果23G网络是CDMA,则是SVLTE,如果23G网络是GSM/UTRAN的,则是SGLTE),这样数据业务使用LTE网络,语音业务用23G网络。可以同时工作。

CSFB则是一种单卡单待的方案,终端只能工作在一个网络下,例如工作在LTE下,当有语音来电时,通过回落的方式回到23G网络下工作,因此采用CSFB方案4G网络和语音是不能同时进行的,注意这里说的是4G网络和语音不能同时进行而不是上网和语音不能同时进行,国内的3大运营商是有区别的,如下:
1.移动4G网络:
移动的3G网络就是移动的痛,移动的网络中当有语音来电时都会选择回落到GSM网络的,极少回落3G网络的,因为移动很清楚自己的3G网络无论是覆盖范围还是信号稳定度都很渣的。大家都知道2G网络不能在打电话的同时连接数据业务,因为移动4G语音回落2G会导致电脑断网的。

2.联通4G网络:
联通3G的WCDMA网络速度快,信号稳定,语音电话时会回落到42Mb/s的3G网络,WCDMA允许通话的同时连接数据业务,从这里可以看出,虽然联通的4G手机如果采用CSFB方案也不支持4G网络和语音同时进行,但是由于其回落到WCDMA网络允许通话的同时连接数据业务,因此语音通话时不会断网,但此时也不是工作在4G模式

3.电信4G网络
由于CDMA与LTE并不是一个体系中的技术,所以LTE语音通话要回落到CDMA,通话结束再返回LTE网络,电信就要在基站上做很大的改动,投入的资金较多的。全球的CDMA运营商都不会选择CSFB方案的。苹果采用了一种折中方案,会同时在CDMA 1x和LTE网络待机,这听起来有点像单卡双待,但CDMA 1x和LTE同时只能有一个进行数据的收发。如果有电话呼入,中断LTE数据业务,把电话接进来的。由于在CDMA 1x和LTE双待机,所以根本就不需要使用回落技术,只要调整阀门,关闭LTE数据收发,就能把通道腾出来,让CDMA 1x进行语音通信。
苹果的这种奇葩的方案,能够让C网运营商稍加改动网络协议就能满足iphone5的需求的,目前这种奇葩方案叫SRLTE。

综上所述,
1、如果终端设备采用的是SGLTE和SVLTE的语音方案,4G网络和语音都是可以同时进行的,不管哪个运营商。
2、采用CSFB的方案的终端设备,移动网络由于会回落到2G,2G又不支持不能在打电话的同时连接数据业务,因此会断网。而联通网络由于回到到的是WCDMA,因此因此语音通话时不会断网,但此时也不是工作在4G模式。
3、SRLTE,这个是专门针对电信CDMA网络的一个方案,采用这种方案的终端设备一样无法同时语音和数据,因此会断网。只有等电信部署好了SRLTE才有更好的体验度。

TDD LTE and FDD LTE

Category : 技术相关

As we know, the LTE mainly covers two types, which are TDD and FDD.  Let’s talk something about TDD LTE and FDD LTE’s Advantages / disadvantages of for cellular communications.

There are a number of the advantages and disadvantages of TDD and FDD that are of particular interest to mobile or cellular telecommunications operators. These are naturally reflected into LTE.

COMPARISON OF TDD LTE AND FDD LTE DUPLEX FORMATS
PARAMETER TDD LTE FDD LTE
Channel reciprocity Channel propagation is the same in both directions which enables transmit and receive to use on set of parameters Channel characteristics different in both directions as a result of the use of different frequencies
Paired spectrum Does not require paired spectrum as both transmit and receive occur on the same channel Requires paired spectrum with sufficient frequency separation to allow simultaneous transmission and reception
Hardware cost Lower cost as no diplexer is needed to isolate the transmitter and receiver. As cost of the UEs is of major importance because of the vast numbers that are produced, this is a key aspect. Diplexer is needed and cost is higher.
UL / DL asymmetry It is possible to dynamically change the UL and DL capacity ratio to match demand UL / DL capacity determined by frequency allocation set out by the regulatory authorities. It is therefore not possible to make dynamic changes to match capacity. Regulatory changes would normally be required and capacity is normally allocated so that it is the same in either direction.
Guard period / guard band Guard period required to ensure uplink and downlink transmissions do not clash. Large guard period will limit capacity. Larger guard period normally required if distances are increased to accommodate larger propagation times. Guard band required to provide sufficient isolation between uplink and downlink. Large guard band does not impact capacity.
Cross slot interference Base stations need to be synchronised with respect to the uplink and downlink transmission times. If neighbouring base stations use different uplink and downlink assignments and share the same channel, then interference may occur between cells. Not applicable
Discontinuous transmission Discontinuous transmission is required to allow both uplink and downlink transmissions. This can degrade the performance of the RF power amplifier in the transmitter. Continuous transmission is required.

 

Advantages and Disadvantages of 4G WIRELESS TECNOLOGY

Category : 技术相关

Today is the day of high data requirement in internet. In most field the wireless system is very widely used. Currently a number of technologies like 1G, 2G, 2.5G, 3G, 3.5G etc.  A new technology is introduced which is called as 4G technology.

Fourth generation wireless system is a packet switched wireless system with wide area coverage and high throughput. It is designed to be cost effective and to provide high spectral efficiency. Data rate of 20mbps is employed. Mobile speed will be up to 200km/hr. The high performance is achieved by the use of long term channel in both time termchannel in both time and frequency, scheduling among users and smart antennas combined with adaptive modulation and power control. Frequency band is 2-8 GHz. it gives the ability for world wide roaming to access cell anywhere.It uses OFDM (ortogonal frequency divisional multiplexing) and Ultra Wide Radio Band(UWB), and Millimeter wireless and smart antenna.4G uses a multi network functional device software which is very helpful for multiple user.

Advantages
-support for interactive multimedia, voice, streaming video, Internet, and other broadband services -IP based mobile system-High speed, high capacity, and low cost per bit. -global access, service portability, and scalable mobile services -Seamless switching and a variety of Quality of

-Better spectral efficiency. Service driven services.
- Better scheduling and call admission control techniques

Disadvantages
-Expensive and hard to implement
-bettery usage is more
-needs complex hardware

Conclusion
There is a need for next generation of wireless technology i.e. 4G which will be a platform for seamless technology providing widespread coverage, band width and power consumption with higher data rates (100Mbps, 150Mbps and 300Mbps, future will update to 1000Mbps, etc.).

路由器不能上网怎么解决

Category : 技术相关

路由器不能上网怎么解决
随着电脑和网络的普及,在家上网已经成为司空见惯的事了,有的家庭可能家中不只一台电脑,这时候为了保证家里各个成员都可以上网有一台路由器就是必备的了。但是有的朋友经常因为配置有误而造成路由器产生故障,那么今天就让编辑给你支支招帮您轻松搞定这些问题。
无法浏览网页
故障现象:网页以不能正常打开,但是QQ之类的程序却可以正常运行。
解决方法:要解决这个问题,建议在路由器和计算机网卡上手动设置DNS服务器地址((ISP局端提供的地址),打开路由器设置界面,找到“网络参数”中的“WAN口参数”的字段,然后在下面手动设置DNS服务器地址。另外,在“DHCP服务”设置项,也需要手动设置DNS服务器和备用的DNS服务器地址,该地址需要从ISP供应商那里获取。
无法进行拨号
故障现象:不能进行正常的拨号程序。
解决方法:这种问题的解决方法比较简单,具体做法是:打开Web浏览器,在地址栏中输入路由器的管理地址,如192.168.1.1,此时系统会要求输入登录密码(该密码可以在产品的说明书上查询到),登陆后进入管理界面,选择菜单“网络参数”下的“WAN口设置选项,在右边主窗口中,“WAN口连接类型”选择“PPPoE”,输入“上网账号”及“上网口令”,点击连接按钮即可。
部分计算机无法正常连接
故障现象:路由器硬件上没有问题,所连接的计算机也没有问题,但是却不能实现正常连接,而局域网中的其他计算机可以正常连接上网。
解决方法:先将被绑定MAC地址的计算机连接至路由器LAN端口(但路由器不要连接Modem或ISP提供的接线),然后,采用路由器的MAC地址克隆功能,将该网卡的MAC地址复制到宽带路由器的WAN端口,接着在未被绑定的计算机上进行如下操作:Windows 2000/XP下按“开始→运行”,输入“cmd/k ipconfig /all”,其中“Physical Address”就是本机MAC地址。

串联两个路由器如何上网

Category : 技术相关

串联两个路由器如何上网
在我们上网的时候通常会发现这样的一种情况,在一根网线已经链接到了一个路由器的接口之后,我们姑且将它称之为路由器A,在路由器A再分出一根线还要链接另外一个路由器,我们称之为路由器B,那么问题是这个路由器…
在我们上网的时候通常会发现这样的一种情况,在一根网线已经链接到了一个路由器的接口之后,我们姑且将它称之为路由器A,在路由器A再分出一根线还要链接另外一个路由器,我们称之为路由器B,那么问题是这个路由器B该怎样实现正常的上网功能呢?
今天我们来谈一下利用两台路由器,网线和电脑这三者的链接方式和设置办法,从而实现最终的双重上网功能。具体的步骤是:首先需要查看一下两款路由器的IP地址是否一致,如果不相同的话那么可以跳过这步,实际上一般的路由器的IP是192.168.0.1。接着进入路由器B的管理界面,找到路由器B的LAN接口,并将路由器B的IP地址设置为192.168.1.1,然后保存。那么以后路由器B的IP就变成了重新设置好的这个地址了。
接着,让让路由器A连接到网络并进入路由器A的管理界面,同时将DNS和子网掩码等信息复制,并在界面上显示出来。然后,将路由器A的LAN口分出来的网线连接到路由器B的WAN接口上,最后在浏览器中输入设置之后的IP地址再进入路由器B。在路由器B中找到其WAN接口,将之设置为静态IP。
将路由器A的 LAN口分出的网线连接到路由器B的WAN口上,再到浏览器中输入修改后的IP地址进入路由器B的管理界面192.168.0.X,这个叉一般表示的是22到254之间任何的参数。其中,子网掩码和DNS的信息与路由器A相同,网关设置为路由器A的管理IP地址,将设置好的IP地址点击保存。
到了此刻,两台路由器就实现了串接,一般当路由器A上网的时候,路由器B连接到电脑之后同样也就可以上网了。