公开(公告)号：US5898679A

公开(公告)日：1999-04-27

申请号：US775238

申请日：1996-12-30

申请人： Loeke Brederveld ,  Jan Hoogendoorn ,  Hendrik Moelard ,  Leo Monteban ,  Rienk Mud

发明人： Loeke Brederveld ,  Jan Hoogendoorn ,  Hendrik Moelard ,  Leo Monteban ,  Rienk Mud

IPC分类号： H04L1/00 ,  H04L1/18 ,  H04L7/00 ,  H04L12/28 ,  H04L12/56 ,  H04L12/66 ,  H04W84/12 ,  H04W88/04 ,  H04B7/14 ,  H04J1/10 ,  H04J3/08

CPC分类号： H04L1/1809 ,  H04L2001/0092 ,  H04W84/12 ,  H04W88/04

摘要： For use in a wireless computer network having a radio relay capable of transmitting messages, a system and method, operable with the radio relay, for selectively repeating a unicast message received from a source end-station only upon some indication that a destination end-station has not received the message. The system includes: (1) a transceiver that receives the unicast message from the source end-station and (2) control circuitry, coupled to the transceiver, that determines whether the destination end-station has received the unicast message and causes the transceiver to refrain from repeating the unicast message if the destination end-station has received the unicast message, the radio relay thereby freed from repeating already-received unicast messages.

摘要翻译： 为了在具有能够发送消息的无线电中继器的无线计算机网络中使用，可以与该无线电中继器一起操作的系统和方法仅在一个目的地终端站的指示上选择性地重复从源端站接收到的单播消息 没有收到消息。 该系统包括：（1）从源终端接收单播消息的收发器，以及耦合到收发器的控制电路，其确定目的终端是否已经接收到单播消息，并使收发信机 如果目的终端已经接收到单播消息，则不重复单播消息，所以无线中继从而避免重复已经接收到的单播消息。

公开(公告)号：US06278877B1

公开(公告)日：2001-08-21

申请号：US08065328

申请日：1993-05-21

申请人： Loeke Brederveld ,  Wilhelmus J. M. Diepstraten ,  Johannes P. N. Haagh ,  Hendrik Moelard ,  Jan Hoogendoorn

发明人： Loeke Brederveld ,  Wilhelmus J. M. Diepstraten ,  Johannes P. N. Haagh ,  Hendrik Moelard ,  Jan Hoogendoorn

IPC分类号： H04B700

CPC分类号： H04W36/30

摘要： A wireless local area network system includes a plurality of base stations connected in a wired local area network. A mobile wireless station can roam through communication cells defined by the base stations. The base stations transmit beacon messages at regular intervals. The mobile station determines the communications quality of the beacon message for the cell in which the mobile station is currently located and if this quality becomes unacceptable, switches to a search mode wherein beacon messages from any base station are received and their communications quality is determined. The mobile station switches to communicate with a base station providing a beacon message with an acceptable communications quality.

摘要翻译： 无线局域网系统包括连接在有线局域网中的多个基站。 移动无线站可以漫游由基站定义的通信小区。 基站以规则的间隔发送信标消息。 移动台确定移动台当前所在小区的信标消息的通信质量，如果该质量变得不可接受，则切换到其中接收来自任何基站的信标消息并确定其通信质量的搜索模式。 移动台切换到与提供具有可接受通信质量的信标消息的基站通信。

公开(公告)号：US4464298A

公开(公告)日：1984-08-07

申请号：US457191

申请日：1983-01-11

申请人： Menso P. Rappoldt ,  Louis F. Pauli ,  Jan Hoogendoorn

发明人： Menso P. Rappoldt ,  Louis F. Pauli ,  Jan Hoogendoorn

IPC分类号： C07J1/00 ,  C07J9/00 ,  C07J21/00 ,  C07J75/00 ,  C07J17/00

CPC分类号： C07J21/006 ,  C07J9/00

摘要： The invention relates to a method of preparing .DELTA.5,7-steroids, in particular 7-dehydrocholesterol compounds, of the general formula: ##STR1## wherein R is a hydrogen atom, a hydroxy group, optionally etherified with a C.sub.1 -C.sub.4 alkanol or esterified with a C.sub.1 -C.sub.4 alkane carboxylic acid, a C.sub.2 -C.sub.5 alkanoyl group, optionally ketalized with a C.sub.1 -C.sub.4 alkanol, or a branched or non-branched, saturated or unsaturated C.sub.1 -C.sub.10 alkyl group, optionally substituted with one or more fluorine atoms or hydroxy groups, which hydroxygroup or groups is (are) optionally etherified with C.sub.1 -C.sub.4 alkanol(s) or esterified with C.sub.1 -C.sub.4 alkane carboxylic acid(s), andR.sup.1, R.sup.2 and R.sup.3 are equal or different and represent hydrogen atoms or hydroxy groups, optionally etherified with C.sub.1 -C.sub.4 alkanols or esterified with C.sub.1 -C.sub.4 alkane carboxylic acids, or wherein R.sup.1 and R.sup.2 together constitute a C.sub.2 -C.sub.4 alkylene dioxy group,by dehydrobrominating 7-bromo-.DELTA.5-steroids under the influence of a fluoride as a base in an organic solvent.

摘要翻译： 本发明涉及一种制备具有以下通式的DELTA 5,7-类固醇，特别是7-脱氢胆固醇化合物的方法：其中R是氢原子，羟基，任选地与C 1 -C 4烷醇醚化，或 用C 1 -C 4烷烃羧酸酯化的C 2 -C 5烷酰基，任选地被C 1 -C 4链烷醇缩合，或任选被一个或多个氟取代的支链或非支链，饱和或不饱和的C1-C10烷基 原子或羟基，其中羟基或基团任选与C 1 -C 4链烷醇醚化或用C 1 -C 4烷烃羧酸酯化，并且R 1，R 2和R 3相同或不同，表示氢原子 或羟基，任选地用C 1 -C 4链烷醇醚化或用C 1 -C 4烷烃羧酸酯化，或其中R 1和R 2一起构成C 2 -C 4亚烷基二氧基，通过在7- 氟化物作为有机溶剂中的碱 nt。