Android Wi-Fi Direct 工作的距离范围
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range of distances in which Wi-Fi direct works
提问by Soheil
I'm developing an android app which is based on WiFi Direct technology(P2P), so I really need to know how many meters is the range of android WiFi direct performance.based on Android API Guides:
我正在开发一个基于 WiFi Direct 技术（P2P）的 android 应用程序，所以我真的需要知道 android WiFi direct 性能的范围是多少米。 基于 Android API 指南：
you can discover and connect to other devices when each device supports Wi-Fi P2P, then communicate over a speedy connection across distances much longer than a Bluetooth connection.
当每个设备都支持 Wi-Fi P2P 时，您可以发现并连接到其他设备，然后通过比蓝牙连接远得多的距离的快速连接进行通信。
but knowing that is not enough for me. because of my aim I need numbers! I mean a range of distances in which Wi-Fi P2P works.
但知道这对我来说还不够。因为我的目标，我需要数字！我的意思是 Wi-Fi P2P 工作的一系列距离。
回答by Simas
Typical Wi-Fi devicesextend their signal up to 100 meters. Source
典型的 Wi-Fi 设备将其信号扩展到 100 米。来源
However the biggest of horrorof Wi-Fi is Line of Sight (LOS) which may drop your range dramatically.
然而，Wi-Fi最大的恐惧是视线 (LOS)，它可能会大大降低您的范围。
That's because Wi-Fi signals at 2.4GHz or 5GHz frequencies. These are easily disrupted by interfering obstacles such as furniture, walls or even mirrors (whose metallic layer reflects the signal) or even water that absorbs the waves. If the app is to be used mostly outside, such obstacle count is supposedly greatly decreased.
这是因为 Wi-Fi 信号的频率为 2.4GHz 或 5GHz。这些很容易被干扰障碍物破坏，例如家具、墙壁甚至镜子（其金属层反射信号），甚至是吸收波的水。如果该应用程序主要在户外使用，则据说此类障碍物数量会大大减少。
Extra:
额外的：
Wi-Fi signal strength is influenced by a factor called attenuation. Here's a Cool Tabledisplaying the materials influence on the signal.
Wi-Fi 信号强度受称为衰减的因素影响。这是一个很酷的表格，显示了材料对信号的影响。
You might also want to keep in mind that Android Wi-Fi P2P (Wi-Fi direct) is available only since API 14 (4.0 ICS).
Though Samsung allowed using the Wi-Fi Direct ability to connectto devices since API 9 (2.3 Gingerbread).
Anyhow you might want to think if users are "there yet", to be using this standard.
您可能还想记住，Android Wi-Fi P2P（Wi-Fi 直连）仅在 API 14 (4.0 ICS) 后可用。尽管从 API 9（2.3 Gingerbread）开始，三星允许使用 Wi-Fi Direct 功能连接到设备。
无论如何，您可能想考虑用户是否“在那里”使用此标准。
I also liked this Videocomparing Galaxy S3 and iPhone 5 connectivity to a GoPro Hero 3 Camera. The maximum range he reached was 100 yards (~90 meters) with perfect LOS.
我也喜欢这个视频，比较 Galaxy S3 和 iPhone 5 与 GoPro Hero 3 相机的连接性。他达到的最大射程是 100 码（约 90 米），并且具有完美的视距。
EDIT:
编辑：
Antenna-Theorya website dedicated completely to antenna's states that:
Antenna-Theory一个完全致力于天线的网站指出：
Wi-Fi Antenna Efficiencies for handheld mobile devices are typically on the order of -6 dB to -2 dB
手持移动设备的 Wi-Fi 天线效率通常在 -6 dB 到 -2 dB 的数量级
While various online sources note that average laptop antenna efficiency is from -3dB to 3dB, which is not that much different from the cell phone.
虽然各种在线资源指出笔记本电脑天线的平均效率在-3dB 到 3dB 之间，这与手机没有太大区别。
You can't really figure out the actual numbersas it all really depends on the surroundings, the target's antennaand the users antenna.
您无法真正计算出实际数字，因为这完全取决于周围环境、目标天线和用户天线。
Still phones tend to have lower range than that of the laptops and it's probably between 50-80 metersin clear sight.
静态手机的范围往往低于笔记本电脑的范围，并且在清晰的视野范围内可能在50-80 米之间。
Sorry but I can't provide more accurate information as i'm no physicist or a technician, and what you're asking for is pretty abstract :)
抱歉，我无法提供更准确的信息，因为我既不是物理学家也不是技术人员，而且您所要求的内容非常抽象:)
回答by CommonGuy
This sitesays the range of WiFi-direct of phones is about 200 feet (~60 meters)while bluetooth has a range of 30 feet (~10 meters).
该网站称，手机的 WiFi-direct 范围约为200 英尺（~60 米），而蓝牙的范围为 30 英尺（~10 米）。
The official Wi-Fi direct site(see under the point "How far does a Wi-Fi Direct connection travel?") states that the maximum range of WiFi-direct is up to 200 meters (which is 656 feet), but I highly doubt that phones already achieve this range...
官方 Wi-Fi Direct 站点（参见“ Wi-Fi Direct 连接能走多远？”）指出 WiFi-direct 的最大范围可达200 米（即 656 英尺），但我高度评价怀疑手机是否已经达到这个范围......
回答by tony9099
"Wi-Fi Direct devices will operate at the same speeds or data rates and range as current Wi-Fi gear. This maximum of about 200 Mbps at 200 feet is much more than the 3 Mbps at 30 feet with Bluetooth. This means you can share and communicate much faster and farther with Wi-Fi Direct."
“Wi-Fi Direct 设备将以与当前 Wi-Fi 设备相同的速度或数据速率和范围运行。在 200 英尺处的最大约 200 Mbps 远高于使用蓝牙在 30 英尺处的 3 Mbps。这意味着您可以使用 Wi-Fi Direct 更快、更远地共享和通信。”
source: http://www.ciscopress.com/articles/article.asp?p=1620205&seqNum=2
来源：http: //www.ciscopress.com/articles/article.asp?p=1620205&seqNum=2
回答by Justin Sweely
I've done my research on this in the past. Similarly with the other answers, I found that the maximum distance "The Wi-Fi Alliance" claims it to reach is 656 feet. I could be wrong, but I feel that it may be possible to connect both devices to an Apple AirPort device and extend it quite a bit.. Of course you can't expect all of your app purchasers to have one, but in the testing phases it may prove to be very useful.
我过去做过这方面的研究。与其他答案类似，我发现“Wi-Fi 联盟”声称达到的最大距离为 656 英尺。我可能是错的，但我觉得可以将两个设备连接到 Apple AirPort 设备并对其进行相当多的扩展。阶段它可能被证明是非常有用的。
