All the rates are based upon that both the Master and Slave are ready to transmit data with every poll and no retransmissions on the air-interface.

The bluetooth controller selects the most appropriate package type depending on the requested payload size and the amount of RF-noice in the environment. In a low noice area, large buffers of application data will be transmitted in several DH5 packages, and very small buffers will be transmitted in one DH1 package. Each of the specified packages fits into one or more timeslots (eg. a DH5 uses 5 timeslots= 5*0.625 msec).

Type	Payload bytes	Asymmetric Forward Transfer ([payload bytes]*8*1000)/([no of slots]*0.625*1000)
DM1	0-17	108.8 kb/s
DH1	0-27	172.8 kb/s
2-DH1 (EDR)	0-54	345.6 kb/s
3-DH1 (EDR)	0-83	531.2 kb/s
DM3	0-121	387.2 kb/s
DH3	0-183	585.6 kb/s
2-DH3 (EDR)	0-367	1174.4 kb/s
3-DH3 (EDR)	0-552	1766.4 kb/s
DM5	0-224	477.8 kb/s
DH5	0-339	723.2 kb/s
2-DH5 (EDR)	0-679	1448.5 kb/s
3-DH5 (EDR)	0-1021	2178.1 kb/s

Running an application on top of the Serial Port Profile.

Example 1. Using small packages:

The Serial Port Profile is based on the L2CAP and the RFCOMM protol.
In a normal data package, 8 bytes of the available payload are used for these protocols. If the controller uses a DM1 package, the application can transfer 1 to 9 bytes.

fig.4

If a PC master application sends a command(max 9 bytes) and a slave application replies with an ack/nack (also max 9 bytes), the theoretical max speed will be (9*8*1000)/(3.75*1000) = 19.2 kb/s because we need to take into account that neither the slave nor the master-application are ready to respond immediately to a request. See fig. 5.

fig.5

If the application package also contains header and length fields as in fig.4, the transfer rate for one byte application payload is: (1*8*1000)/(3.75*1000)= 2.1 kb/s

[EDR Enhanced Data Rate, only available in Bluetooth version 2.0]