Laird BTM410, User Manual

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BTM410/411
Bluetooth
®
AT Data Module
21 www.lairdtech.com Laird Technologies
AT COMMAND SET
REFERENCE AT COMMAND SET
REFERENCE
7. AT+BTE? {Query outgoing EIR Data}
This command prints the outgoing EIR data that is currently set up
Response:
<cr,lf>
<EIR-Data>
<cr,lf>OK<cr,lf>
Secure Simple Pairing (SSP)
Secure Simple Pairing (SSP) has been introduced since Bluetooth 2.1 + EDR. It aims to increase the
security provided by a Bluetooth link whilst making the pairing process more user friendly.
There are white papers about SSP available through the internet (provided by the Bluetooth SIG and
other companies), explaining the mechanisms and backgrounds of SSP. They can be found by searching
the internet for e.g. “Bluetooth Secure Simple Pairing”. Please familiarize with those documents to get a
better understanding of SSP and the following settings.
1. Security Level (S320)
The security level is defined in the BT2.1+EDR specification [1], vol3, Generic Access Profile (Table
5.7).
There are 4 Levels providing different levels of security (Table 3-10):
Table 3-10: Security levels
Security Level Characteristics Comment
Level 3

MITM protection (MITM = “Man in
the Middle” attack)

Encryption

User interaction
High security
Level 2

No MITM protection

Encryption
Medium Security
Level 1

No MITM protection

(No) Encryption (1)

Minimal user interaction
Low Security
Level 0

No MITM protection

No Encryption

Minimal user interaction
Permitted only for
service discovery
(1) Although encryption is not necessary for security level 1, encryption will always be enabled
because this specification mandates encryption for all services other than SDP (service discovery).
The security level is defined by S Register 320 and is referenced at boot time only. Hence the
register must be saved by “AT&W “ and the module must be power cycled (or “ATZ”) subsequently.
S320 = 3 will overwrite the setting of S Register 322 (enable MITM).
The security level will remain the same until next power cycle and is valid for all profiles and
services
of the module. For SDP (service discovery profile), security level 0 is always assigned internally.