Some further information from this 2006 report
Table 8: ETSI notified essential patents by firm
Firm Claimed / number of unique essential patents
Nokia 248
Ericsson 244
Qualcomm 228
InterDigital 168
Samsung 86
Motorola 54
Philips 45
Siemens(*) 38
Asustek 23
Alcatel 20
Mitsubishi (*) 18
Nortel 15
Toshiba, ETRI (*), Voiceage, France Telecom, Evolium, Sun Microsystems, OKI, Tantivy communications, IPR licensing, Salbu research & development, Cisco systems, Robert Bosch, Canon, CCL/ITRI, Media farm, Aepona, Bijitec, Wi-lan, Telia - Each claiming 5 or less
Patents
Coding technologies, Italtel, Lucent, NEC, Omnipoint, Texas Instruments - Blanket claim
Source: Bekkers & West (2006). Note: Firms market with an (*) agreed to license via W-CDMA Patent
Licensing Programme