6.51 (HCI: 7.5.3) Read_Link_Quality 6.51（HCI：7.5.3）Read_Link_Quality
This command obtains a value in the range 0 to 0xff, describing the quality of an ACL connection.
此命令获得一个说明
ACL连接质量的值，其介于
0至0xff之间。
The value's meaning is manufacturer-specific. 这个值的意思是制造商特定的。
The value is derived from an averaged bit error rate (BER) measurement, updated as packets are received.
该值是源于平均误码率（
BER）的测量，接收数据包时更新。
The BER value is derived from parts of radio packets that support FEC error correction:
误码率是来自部分无线数据包，支持? All packets' headers ?所有数据包的包头
? The payloads of DM1, DM3, DM5, HV1 and HV2 packets ?DM1，DM3，DM5，HV1和HV2包的有效载荷? The data parts of DV packets ?DV包的数据部分
The technique used to derive BER values is not precise; it is intended only to give an indication instrument.
该手法用于计算误码率的值是不准确的，它只是为了指示链路的质量，而不是作为一个精确的测量指示。
of link
quality
rather
than act as a precise,
calibrated
FEC的错误：
. . .
Links' BER values are used internally to adapt to changes in link quality, notably to support CQDDR (Channel Quality Driven Data Rate).
链路的误码率值是在内部使用，道质量确定数据速率）。
The HCI command's values are as follows. HCI命令的值如下。
? Between 0xff and 0xd7 each bit distance represents 0.0025% BER. Thus: ?
在0xff和0xd7间的每个位代表
0.0025％的误码率。因此：以适应变化的高质量链接，
特别是支持CQDDR（根据信
? Between 0xd6 and 0x5a each bit distance represents 0.08% BER. Thus: ?在0xd6和0x5a间的每个位代表误码率
0.08％。因此：
. . .
? Between 0x59 and 0x00 each bit distance represents 0.64% BER. ?在0x59和0x00间的每个位代表误码率
0.64％。
As a rule of thumb, a link with a BER between 0 and 0.1% is workable. 根据经验，链路的误码率在
0和0.1%之间是可行的。
Trying to run a link with a BER above 1% gives poor results. 尝试运行一个误码率大于Note: 注意：
For EDR links these tables are not valid. It is not possible to convert link quality into BER.
这些表对于EDR链路无效。它不可能转化为链路质量的误码率。
1%的连接会给出差的结果。
. . .
6.52 (HCI: 7.5.4) Read_RSSI 6.52（HCI：7.5.4）Read_RSSI
A common user hope is to use this command's return values as the basis of a general-purpose signal strength meter.
通常用户希望使用此命令返回基于多方信号强度计量的值。Unfortunately, role.
不幸的是，这个命令，由While a link's
[BT1.1]指定，这个角色几乎是无用的。
the command, as specified
by [BT1.1],
is almost useless for this
received signal strength is within the Golden Receive Power Range
the command returns an RSSI value of zero.
在链路处于黄金接收功率范围内时，此命令返回一个零的
RSSI值。
The Golden Receive Power Range is normally around 20dBm wide, crudely equating to a physical range factor of ten. (For example, between 1m and 10m the RSSI value could be zero.)
黄金接收功率范围是通常在
20dBm宽度周围，粗略的等同于
10的物理范围。（例如，1
米和10米之间的RSSI的值都可以是零。）
The RSSI value only goes positive or negative when the received signal slips outside the Golden Range.
RSSI的值仅仅是变正或负，当收到的信号在黄金范围外时。Where dynamic
power control
is
available,
the
firmware's
LM emits
LMP_incr_power_req or LMP_decr_power_req messages to the Bluetooth peer to try to bring the received signal strength back into the Golden Range.
当动态功率控制是可用的，
固件的LM发出LMP_incr_power_req或LMP_decr_power_req
消息给蓝牙匹配尝试把接收到的信号强度调回黄金范围。
[BT1.1] requires only that the function return a negative value when the RSSI is below the Golden Range, zero within it, and a positive value when the RSSI is above the Golden Range.
. . .
[BT1.1]只要求函数在低于黄金范围时返回一个负的时返回一个正的
RSSI。
RSSI，零也在其中，高于黄金范围
? When the RSSI is above the Golden Range, the firmware returns a positive number.
?当RSSI高于黄金范围时，固件返回一个正数。The value is an approximation the RSSI.
该值是一个近似的
dB，在黄金范围的顶部和
RSSI之间。
of the dB between the top of the Golden Range and
The value is very crude: it can be ± 5dB from the real value, there is no
be monotonic.
RSSI将返
guarantee that a constant RSSI will give a constant return value, and thus there is no guarantee that the mapping from RSSI to the returned value will
该值是很简陋：它可以与真实的值相差±回一个恒定不变的值，所以是不能保证从
5dB，但不能保证一个恒定不变的RSSI的映射到返回的值将是单调的。
? When the RSSI is within the Golden Range, the firmware returns zero. ?当 RSSI在黄金范围内时，固件返回零。
? When the RSSI is below the Golden Range, the firmware returns a negative number.
?当RSSI低于黄金范围时，固件返回一个负数。
The value is an approximation of the dB between the RSSI and the bottom of the Golden Range.
该值是一个近似的
dB，在黄金范围的底部和
RSSI之间。
±
The value is even more crude than for positive values: it can be more than
5dB from the real value, there is no guarantee that a constant RSSI will give a
constant return value, thus there is no guarantee that the mapping from RSSI to the returned value will be monotonic, and the value clips at a minimum of approximately -10dB.
该值甚至比正值更粗糙：- 10dB的最低值剪辑。
它可以与真实的值差±
5dB，但不能保证一个恒定不变的
RSSI
将返回一个恒定不变的值，因此也不能保证，从返回的映射的RSSI值将是单调的，并在约
. . .
CSR蓝牙固件关于对信号强度RSSI的应用
