Just curious. - What was the TX power of pagers? - Which band did you use for your pagers? - Where were pagers mounted? - What did you see on the spectrum? - What do you mean 电磁性质非常混乱? multipath? Sorry. Can not input Chinese now.
【在 i******r 的大作中提到】 : 你的描述还是有专业性的,谢谢。看来是没有这种东西,只能帮他们搞些一般rfid的东 : 西试试看了,symbol这个公司现在还存在啦? 以前我做管理咨询忽悠人时,还接触过 : 这家。 : : rfid : relay : unit
f*i
28 楼
跟steve jobs开发布会叫大家把手机关掉一个道理
【在 l**n 的大作中提到】 : Just curious. : - What was the TX power of pagers? : - Which band did you use for your pagers? : - Where were pagers mounted? : - What did you see on the spectrum? : - What do you mean 电磁性质非常混乱? multipath? : Sorry. Can not input Chinese now. : : rfid : relay
l*n
29 楼
你这话说得阴阳怪气的。 我只是想知道pager为什么会fail。
【在 f****i 的大作中提到】 : 跟steve jobs开发布会叫大家把手机关掉一个道理
l*n
30 楼
那个部分gave up?能不能展开说说。 Walmart is the largest RFID consumer in this world right now.
【在 f****i 的大作中提到】 : Walmart tried it and gave up.
f*i
31 楼
读取率不够
【在 l**n 的大作中提到】 : 那个部分gave up?能不能展开说说。 : Walmart is the largest RFID consumer in this world right now.
【在 l**n 的大作中提到】 : Just curious. : - What was the TX power of pagers? : - Which band did you use for your pagers? : - Where were pagers mounted? : - What did you see on the spectrum? : - What do you mean 电磁性质非常混乱? multipath? : Sorry. Can not input Chinese now. : : rfid : relay
I am not in the pager business. So, I do not have much knowledge on this. However, TX power = 0 is passive RFID. Based on earlier discussion, I am not sure the pager in pikleyano's post is with 0 TX power. http://www.mitbbs.com/article/PDA/31724065_0.html But, I could be wrong.
Non-sense story from RFID journal Sound like people saying, "hey, the stock market raised from 6600 to 12000 since March 2009" Even Target backed out from UHF RFID tags.
WMT, JCP, MACY's are all expanding their UHF RFID deployments. 你不是业界人士。
【在 f****i 的大作中提到】 : Non-sense story from RFID journal : Sound like people saying, "hey, the stock market raised from 6600 to 12000 : since March 2009" : Even Target backed out from UHF RFID tags.
f*i
42 楼
whatever do you know both AXXXX and IXXXXX failed IPO?
【在 l**n 的大作中提到】 : WMT, JCP, MACY's are all expanding their UHF RFID deployments. : 你不是业界人士。
power level 我们从 passive 的,到几十毫瓦的都考虑过,当然,passive 的就是 painstorming 的时候提出来搞笑的... 当场就被枪毙了。 band 的选择,最后是定了2个方案,900M 和 2.4G,2.4G range 远一些,但是一般来 说比较饱和了,throughput 可能不太高,但是如果是在轮船上用的话,干扰应该会相 对少些(这是我们想当然的assumption,我们都没上过货轮...)。 mount 一般 assume 在 container 面积小的那个侧面,因为container 是摞在一起的 ,上下肯定不可行,面积大的侧面,一般也要前后堆积,所以只有面积小的侧面,会有 一小段缝隙,像一个tunnel 一样。 至于电磁性质方面,我纯是打酱油的,我当时是负责 mesh network 的 MAC 和 routing 的,这方面专门有个做modern physics 的人在做。我就是看频谱就是在开会 的时候,坐在下面看花花绿绿的觉得挺开心的... 本科的时候电磁本来就是死记硬背 Maxwells equation 的各种变形,然后蒙过的... 所以我只记住了结论,到底在底下那 个小空间里,电磁波是怎样传播的,我就不懂了。我只知道其中一个和我的task 联系 比较紧密的问题,就是在下面信号的 multipath 非常严重,不过还好,这个不是很 time sensitive 的application,收到重复的信息我其实不是太在乎的... 但是做天线 的哥们一天的到晚苦大仇深的样子...
【在 l**n 的大作中提到】 : Just curious. : - What was the TX power of pagers? : - Which band did you use for your pagers? : - Where were pagers mounted? : - What did you see on the spectrum? : - What do you mean 电磁性质非常混乱? multipath? : Sorry. Can not input Chinese now. : : rfid : relay