LEASES - Narrative (Details)		12 Months Ended
	May 01, 2020 USD ($) lease	Dec. 31, 2021 USD ($) lease renewal_option	Dec. 31, 2020 USD ($)	Oct. 06, 2021 USD ($) ft²
Lessee, Lease, Description [Line Items]
Number of operating lease | lease		2
Number of non-cancelable leases | lease		2
Restricted cash		$ 55,000	$ 0
Number of renewal options recognized | renewal_option		0
Finance lease liability		$ 175,000
Operating lease cost		1,219,000	1,132,000
Cash paid for operating lease liabilities		777,000	613,000
Finance lease right-of-use asset amortization		41,000	0
Research and Development Expense
Lessee, Lease, Description [Line Items]
Operating lease cost		804,000	812,000
Finance lease right-of-use asset amortization		41,000	3,000
Selling, General and Administrative Expenses
Lessee, Lease, Description [Line Items]
Operating lease cost		$ 415,000	320,000
Sublease Agreement | Sonim Technologies, Inc.
Lessee, Lease, Description [Line Items]
Area of property | ft²				8,416
Initial, monthly rent				$ 12,500
Renewal term				1 year
Renewal, monthly rent				$ 13,250
Lease Amendment
Lessee, Lease, Description [Line Items]
Operating lease renewal periods	3 months
Number of leases amended | lease	1
Base rent deferral period	3 months
Operating expense deferral period		3 months
Lab Equipment Lease
Lessee, Lease, Description [Line Items]
Finance lease term		60 months
Finance lease interest rate		5.99%
Finance lease, right-of-use asset		$ 204,000
Finance lease liability		204,000
Office Building | Letter of Credit
Lessee, Lease, Description [Line Items]
Security deposit		$ 50,000
Operating lease deposit, letter of credit	$ 200,000
Line of credit facility, annual step down of no defaults			$ 50,000
Minimum | Facilities
Lessee, Lease, Description [Line Items]
Operating lease renewal periods		2 years
Maximum | Facilities
Lessee, Lease, Description [Line Items]
Operating lease renewal periods		5 years
Maximum | Facilities and Equipment
Lessee, Lease, Description [Line Items]
Operating lease term		12 months